Datasheet MC44603P Datasheet (Motorola)

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Fixed Frequency, Variable Frequency,
Standby Mode

The MC44603 is an enhanced high performance controller that is
specifically designed for off–line and dc–to–dc converter applications. This
device has the unique ability of automatically changing operating modes if
the converter output is overloaded, unloaded, or shorted, offering the
designer additional protection for increased system reliability . The MC44603
has several distinguishing features when compared to conventional SMPS
controllers. These features consist of a foldback facility for overload
protection, a standby mode when the converter output is slightly loaded, a
demagnetization detection for reduced switching stresses on transistor and
diodes, and a high current totem pole output ideally suited for driving a power
MOSFET. It can also be used for driving a bipolar transistor in low power
converters (< 150 W). It is optimized to operate in discontinuous mode but
can also operate in continuous mode. Its advanced design allows use in
current mode or voltage mode control applications.

Current or Voltage Mode Controller

• Operation up to 250 kHz Output Switching Frequency

• Inherent Feed Forward Compensation

• Latching PWM for Cycle–by–Cycle Current Limiting

• Oscillator with Precise Frequency Control

High Flexibility

• Externally Programmable Reference Current

• Secondary or Primary Sensing

• Synchronization Facility

• High Current Totem Pole Output

• Undervoltage Lockout with Hysteresis

Safety/Protection Features

• Overvoltage Protection Against Open Current and Open Voltage Loop

• Protection Against Short Circuit on Oscillator Pin

• Fully Programmable Foldback

• Soft–Start Feature

• Accurate Maximum Duty Cycle Setting

• Demagnetization (Zero Current Detection) Protection

• Internally Trimmed Reference

GreenLine Controller: Low Power Consumption in Standby Mode

• Low Startup and Operating Current

• Fully Programmable Standby Mode

• Controlled Frequency Reduction in Standby Mode

• Low dV/dT for Low EMI Radiations

GreenLine is a trademark of Motorola, Inc.

This document contains information on a new product. Specifications and information herein
are subject to change without notice.

MOTOROLA ANALOG IC DEVICE DATA

MIXED FREQUENCY MODE

GREENLINE PWM*

CONTROLLER:

V ARIABLE FREQUENCY,

FIXED FREQUENCY,

ST ANDBY MODE

* PWM = Pulse Width Modulation

16

1

P SUFFIX

PLASTIC PACKAGE

CASE 648

16

1

DW SUFFIX

PLASTIC PACKAGE

CASE 751G

(SOP–16L)

PIN CONNECTIONS

1

V

CC
V

2

C

Output

3

Gnd

4

Foldback Input

Overvoltage

Protection (OVP)

Current Sense Input

Demag Detection

5
6

7
8

(Top View)

ORDERING INFORMATION

Operating

Device

MC44603P
MC44603DW SOP–16L

 Motorola, Inc. 1996 Rev 0

Temperature Range

TA = –25° to +85°C

16

R

ref

R

Frequency

15

Standby
Voltage Feedback

14

Input
Error Amp Output

13

R

12

Power Standby

Soft–Start/D

11

Voltage Mode
C

10

T

Sync Input

9

Package

Plastic DIP–16

max

/

1

MC44603

pgg

OL

V

I

mA

0.1

1.0

MAXIMUM RATINGS

Rating Symbol Value Unit

Total Power Supply and Zener Current (ICC + IZ) 30 mA
Supply Voltage with Respect to Ground (Pin 4) V

Output Current (Note 1) mA

Source I

Sink I
Output Energy (Capacitive Load per Cycle) W 5.0 µJ
RF

, CT, Soft–Start, R

Stby

Foldback Input, Current Sense Input,
E/A Output, Voltage Feedback Input,
Overvoltage Protection, Synchronization Input

Synchronization Input

High State Voltage V

Low State Reverse Current V
Demagnetization Detection Input Current mA

Source I

Sink I
Error Amplifier Output Sink Current I
Power Dissipation and Thermal Characteristics

P Suffix, Dual–In–Line, Case 648

Maximum Power Dissipation at TA = 85°C P
Thermal Resistance, Junction–to–Air R

DW Suffix, Surface Mount, Case 751G

Maximum Power Dissipation at TA = 85°C P

Thermal Resistance, Junction–to–Air R
Operating Junction Temperature T
Operating Ambient Temperature T

NOTES: 1. Maximum package power dissipation limits must be observed.

2. ESD data available upon request.

ref

, RP

Inputs V

Stby

demag–ib (Source)

C

V

CC

O(Source)

O(Sink)

in

V

in

IH
IL

demag–ib (Sink)

E/A (Sink)

D

θJA

D

θJA

J
A

18 V

–750

750

–0.3 to 5.5 V

–0.3 to

VCC + 0.3

VCC + 0.3 V

–20 mA

–4.0

10
20 mA

0.6 W

100 °C/W

0.45 W
145 °C/W

150 °C

–25 to +85 °C

V

ELECTRICAL CHARACTERISTICS (V

for min/max values TA = –25° to +85°C [Note 4], unless otherwise noted.)

Characteristic

OUTPUT SECTION

Output Voltage (Note 5) V

Low State (I

Low State (I

High State (I

High State (I

Output Voltage During Initialization Phase V

VCC = 0 to 1.0 V, I
VCC = 1.0 to 5.0 V, I

= 5.0 to 13 V,

CC
Output Voltage Rising Edge Slew–Rate (CL = 1.0 nF, TJ = 25°C) dVo/dT – 300 – V/µs
Output Voltage Falling Edge Slew–Rate (CL = 1.0 nF, TJ = 25°C) dVo/dT – –300 – V/µs

ERROR AMPLIFIER SECTION

Voltage Feedback Input (V
Input Bias Current (VFB = 2.5 V) I
Open Loop Voltage Gain (V

NOTES: 3. Adjust VCC above the startup threshold before setting to 12 V.

4.Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.

5.VC must be greater than 5.0 V.

= 100 mA)

Sink

= 500 mA)

Sink

Source
Source

= 200 mA)
= 500 mA)

= 10 µA

Sink

= 100 µA

Sink

= 1.0

Sink

E/A out

E/A out

= 2.5 V) V

= 2.0 to 4.0 V) A

and VC = 12 V, [Note 3], R

CC

= 10 kΩ, CT = 820 pF, for typical values TA = 25°C,

ref

Symbol Min Typ Max Unit

V

OL

V

OH

OL

FB

FB–ib

VOL

–
–

–
–

– –
–
–

–

2.42 2.5 2.58 V
–2.0 –0.6 – µA

65 70 – dB

1.0

1.4

1.5

2.0

0.1

1.2

2.0

2.0

2.7

1.0

1.0

V

2

MOTOROLA ANALOG IC DEVICE DATA

MC44603

ELECTRICAL CHARACTERISTICS (continued) (V

and VC = 12 V , [Note 3], R

CC

= 10 kΩ, CT = 820 pF , for typical values TA = 25°C,

ref

for min/max values TA = –25° to +85°C [Note 4], unless otherwise noted.)

Characteristic

Symbol Min Typ Max Unit

ERROR AMPLIFIER SECTION (continued)

Unity Gain Bandwidth BW MHz

TJ = 25°C – 4.0 –
TJ = –25° to +85°C – – 5.5

Voltage Feedback Input Line Regulation (VCC = 10 to 15 V) V

FBline–reg

–10 – 10 mV

Output Current mA

Sink (V

TA = –25° to +85°C

Source (V

TA = –25° to +85°C

= 1.5 V, VFB = 2.7 V)

E/A out

= 5.0 V, VFB = 2.3 V)

E/A out

I

Sink

I

Source

2.0 12 –

–2.0 – –0.2

Output Voltage Swing V

High State (I
Low State (I

E/A out (source)

E/A out (sink)

= 0.5 mA, VFB = 2.3 V) V

= 0.33 mA, VFB = 2.7 V) V

OH

OL

5.5 6.5 7.5
– 1.0 1.1

REFERENCE SECTION

Reference Output Voltage (VCC = 10 to 15 V) V
Reference Current Range (I
Reference Voltage Over I

= V

ref
Range ∆V

ref

, R = 5.0 k to 25 kΩ) I

ref/Rref

ref

ref

ref

2.4 2.5 2.6 V

–500 – –100 µA

–40 – 40 mV

OSCILLATOR AND SYNCHRONIZATION SECTION

Frequency f

OSC
TA = 0° to +70°C 44.5 48 51.5
TA = –25° to +85°C 44 – 52

Frequency Change with Voltage (VCC = 10 to 15 V) ∆f
Frequency Change with Temperature (TA = –25° to +85°C) ∆f
Oscillator Voltage Swing (Peak–to–Peak) V
Ratio Charge Current/Reference Current I

/∆V – 0.05 – %/V

OSC

/∆T – 0.05 – %/°C

OSC

OSC(pp)

1.65 1.8 1.95 V

charge/Iref

TA = 0° to +70°C (VCT = 2.0 V) 0.375 0.4 0.425
TA = –25° to +85°C 0.37 – 0.43

Fixed Maximum Duty Cycle = I

discharge

Ratio Standby Discharge Current versus IR F

TA = 0° to +70°C IR F

/(I

discharge

+ I

(Note 6) I

Stby

) D 78 80 82 %

charge

disch–Stby

Stby

/ –

0.46 0.53 0.6

TA = –25° to +85°C (Note 8) 0.43 – 0.63

VR F
Frequency in Standby Mode (RF
Current Range IR F
Synchronization Input Threshold Voltage (Note 7) V

Synchronization Input Current I
Minimum Synchronization Pulse Width (Note 8) T

Stby

(IR F

= 100 µA) VR F

Stby

(Pin 15) = 25 kΩ) F

Stby

Stby

Stby

Stby

inthH

V

inthL

Sync–in

Sync

2.4 2.5 2.6 V
18 21 24 kHz

–200 – –50 µA

3.2

0.45

3.7

0.7

4.3

0.9

–5.0 – 0 µA

– – 0.5 µs

UNDERVOLTAGE LOCKOUT SECTION

Startup Threshold V
Output Disable Voltage After Threshold T urn–On (UVLO 1) V

stup–th

disable1

13.6 14.5 15.4 V

TA = 0° to +70°C 8.6 9.0 9.4
TA = –25° to +85°C 8.3 – 9.6

Reference Disable Voltage After Threshold T urn–On (UVLO 2) V

NOTES: 13. Adjust VCC above the startup threshold before setting to 12 V.

14. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.

16. Standby is disabled for VR P

17. If not used, Synchronization input must be connected to Ground.

18. Synchronization Pulse Width must be shorter than T

< 25 mV typical.

Stby

OSC

= 1/f

OSC

.

disable2

7.0 7.5 8.0 V

kHz

–

V

V

MOTOROLA ANALOG IC DEVICE DATA

3

MC44603

ELECTRICAL CHARACTERISTICS (continued) (V

for min/max values TA = –25° to +85°C [Note 4], unless otherwise noted.)

Characteristic

DEMAGNETIZATION DETECTION SECTION (Note 9)

Demagnetization Detect Input

Demagnetization Comparator Threshold (V
Propagation Delay (Input to Output, Low to High) – – 0.25 – µs

Input Bias Current (V
Negative Clamp Level (I
Positive Clamp Level (I

SOFT–START SECTION (Note 11)

Ratio Charge Current/I

TA = 0° to +70°C 0.37 0.4 0.43

TA = –25° to +85°C 0.36 – 0.44
Discharge Current (V
Clamp Level V
Duty Cycle (R

Duty Cycle (V

OVERVOLTAGE SECTION

Protection Threshold Level on V
Propagation Delay (V
Protection Level on V

TA = 0° to +70°C 16.1 17 17.9

TA = –25° to +85°C 15.9 – 18.1
Input Resistance – kΩ

TA = 0° to +70°C 1.5 2.0 3.0

TA = –25° to +85°C 1.4 – 3.4

FOLDBACK SECTION (Note 10)

Current Sense Voltage Threshold (V
Foldback Input Bias Current (V

STANDBY SECTION

Ratio IR P

TA = 0° to +70°C 0.37 0.4 0.43

TA = –25° to +85°C 0.36 – 0.44
Ratio Hysteresis (Vh Required to Return to Normal Operation from Standby

Operation)

TA = 0° to +70°C 1.42 1.5 1.58

TA = –25° to +85°C 1.4 – 1.6
Current Sense Voltage Threshold (VR P

CURRENT SENSE SECTION

Maximum Current Sense Input Threshold

(V
Input Bias Current I
Propagation Delay (Current Sense Input to Output at VTH of

MOS transistor = 3.0 V)

TOTAL DEVICE

Power Supply Current I

Startup (VCC = 13 V with VCC Increasing) – 0.3 0.45

Operating TA = –25° to +85°C (Note 3) 13 17 20
Power Supply Zener Voltage (ICC = 25 mA) V
Thermal Shutdown – – 155 – °C

NOTES: 13. Adjust VCC above the startup threshold before setting to 12 V.

Stby/Iref

feedback (Pin 14)

14. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.

19. This function can be inhibited by connecting Pin 8 to Gnd. This allows a continuous current mode operation.

10. This function can be inhibited by connecting Pin 5 to VCC.

11. The MC44603 can be shut down by connecting the Soft–Start pin (Pin 11) to Ground.

soft–start

soft–start
soft–start (Pin 11)

OVP
CC

= 65 mV) I

demag

= –2.0 mA) C

demag

= 2.0 mA) C

demag

ref

= 1.0 V) I

= 12 kΩ)

= 0.1 V)

OVP

> 2.58 V to V

foldback (Pin 5)

= 2.3 V and V

out

foldback (Pin 5)

Stby (Pin 12)

foldback (Pin 6)

Decreasing) V

Pin 9

Low) 1.0 – 3.0 µs

= 0 V) I

and VC = 12 V , [Note 3], R

CC

I

D

soft–start 12k

D

= 0.9 V) V

foldback–lb

IR P

Vh/VR P

= 1.0 V) V

= 1.2 V)

= 10 kΩ, CT = 820 pF , for typical values TA = 25°C,

ref

Symbol Min Typ Max Unit

demag–th

demag–lb

L(neg)
L(pos)

ss(ch)/Iref

discharge

ss(CL)

soft–start

V

OVP–th

VCC

prot

CS–th

Stby/Iref

Stby

CS–Stby

V

CS–th

CS–ib

– – 120 200 ns

CC

Z

50 65 80 mV

–0.5 – – µA

– –0.38 – V
– 0.72 – V

1.5 5.0 – mA

2.2 2.4 2.6 V
36

–

2.42 2.5 2.58 V

0.86 0.89 0.9 V
–6.0 –2.0 – µA

0.28 0.31 0.34 V

0.96 1.0 1.04 V

–10 –2.0 – µA

18.5 – – V

42

–

49

0

–

%

V

–

–

mA

4

MOTOROLA ANALOG IC DEVICE DATA

MC44603

r

e

Representative Block Diagram

Demag

Detect

Sync
Input

C

C

R

Pwr Stby

Feed–

back

Compen–

sation

Foldback

Input

10

T

12

14

13

8

9

T

5

Negative

Active

Clamp

0.4 I

ref

1.0 V

1.6 V

0.4 I

+

+

V

ref

ref

2.5 V

65 mV

3.7 V

+

3.6 V

0.4 I

ref

V

refVref

V

CC

1.0 mA

0.7 V

R

Q

S

+

+

R

Q

S

ref

0.8 I

2R

0.6 I

Error Amplifier

V

Demag Out

R

Q

S

V

refVref

ref

I

Discharge/2

Synchro

V

OSC prot

I

Discharge

0.25
IF

Stby

Current Mirror X2

1.0 V

RF

Stby

RF

V

OSC

V

ref

0.2 I

ref

Stby

2.4 V

15 16

V

refIref

0.4 I

ref

1.6 V

Reference

Block

Thermal

Shutdown

V

ref

+

5.0 mA

R

ref

V

ref

UVLO2

V

CC

1

OVP

ref

11.6 k

2.0 k

V

CC

+

9.0 V

18.0 V

V

CC

V

C

2

Output

3

4

Gnd

OVP

6

R

Current
Sense Input

7

+

V

CC

14.5 V/7.5 V

IF

Stby

S

Q

R

2.0
Delay

V

ref

µ

5.0
Delay

+

2.5 V

µ

s

s

UVLO1

V
Out

V

OVP

V

aux

To Powe

Transform

= Sink only

= Positive True Logic

MOTOROLA ANALOG IC DEVICE DATA

SS/D

11

R

SS

This device contains 243 active transistors.

/VM

max

C

SS

5

MC44603

0
0
0
0

0

100

Ω

, TIMING RESISTANCE (k )

ref

R

CT = 2200 pF

10 k

52
51
50
49
48

Figure 1. Timing Resistor versus

Oscillator Frequency

CT = 100 pF

CT = 500 pF

f

, Oscillator Frequency (Hz)

OSC

VCC = 16 V

TA = 25

CT = 1000 pF

Figure 3. Oscillator Frequency

versus T emperature

Figure 2. Standby Mode Timing Capacitor

versus Oscillator Frequency

10000

VCC = 16 V

°

°

C

RF

= 2.0 k

Stby

RF

= 5.0 k

100010

, TIMING CAPACIT OR (pF)

T

C

3003.0
10 k

Stby

RF

= 27 k

Stby

RF

Stby

100 k100 k 1.0 Meg1.0 Meg

f

, Oscillator Frequency (Hz)

OSC

= 100 k

TA = 25

R

= 10 k

ref

C

Figure 4. Ratio Charge Current/Reference

Current versus Temperature

0.43

0.42

0.41

0.40
47
46

, OSCILLAT OR FREQUENCY (kHz)

45

OSC

f

44

–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (°C)

VCC = 12 V

R

= 10 k

ref

CT = 820 pF

Figure 5. Output Waveform Figure 6. Output Cross Conduction

600
400
200

–200
–400

, OUTPUT CURRENT (mA)

–600

O

I

–800

–1000

Current

0

Voltage

VCC = 12 V

CL = 2200 pF

°

C

TA = 25

70
60
50
40
30

20
10
0

–10

0.39

= RATIO CHARGE CURRENT/I

REFERENCE CURRENT

ref

/I

0.38

charge

0.37

–50 –25 0 25 50 75 100

70

VCC = 12 V

60

CL = 2200 pF

TA = 25

50
40
30
20

V

10

, OUTPUT DRIVE VOL TAGE (V)

, OUTPUT DRIVE VOL TAGE (V)

O

O

V

V

–10

O

0

I

CC

TA, AMBIENT TEMPERATURE (°C)

°

C

Current

Voltage

1.0

µ

s/Div1.0 µs/Div

VCC = 12 V

R

= 10 k

ref

CT = 820 pF

300
200
100
0
–10

–20
–30
–40
–50

6

MOTOROLA ANALOG IC DEVICE DATA

MC44603

Figure 7. Oscillator Discharge Current

versus T emperature

500

A)

475

µ

450
425
400
375
350

, DISCHARGE CURRENT (

325

disch

I

300

–50 –25 0 25 50 75 100

VCC = 12 V

R

= 10 k

ref

CT = 820 pF

°

C)

Figure 9. Sink Output Saturation Voltage

versus Sink Current

Sink Saturation

(Load to VCC)

1.6

1.2

Figure 8. Source Output Saturation Voltage

versus Load Current

2.5

2.0

1.5

1.0

, SOURCE OUTPUT SATURATION VOLT AGE (V)

OH

0 100 200 300 400 500

V

I

, OUTPUT SOURCE CURRENT (mA)TA, AMBIENT TEMPERATURE (

source

Figure 10. Error Amplifier Gain and Phase

versus Frequency

802.0

60

40

VCC = 12 V
G = 10
Vin = 30 mV

VO = 2.0 to 4.0 V

RL = 100 k
TA = 25

VCC = 12 V

R

= 10 k

ref

CT = 820 pF

°

C

TA = 25

°

C

140

0.8
TA = 25°C

0.4

, SINK OUTPUT SA TURATION VOLT AGE (V)

0

OL

V

0 100

200 300 400 500

I

, SINK OUTPUT CURRENT (mA)

sink

VCC = 12 V

µ

s Pulsed Load

80

120 Hz Rate

Figure 11. Voltage Feedback Input

versus T emperature

2.60
VCC = 12 V

2.55

2.50

2.45

, VOLTAGE FEEDBACK INPUT (V)

FB

V

2.40

–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (

G = 10

VO = 2.0 to 4.0 V

RL = 100 k

°

C)

GAIN (dB)

20

0

–20

1001.0 10 1000

f, FREQUENCY (kHz)

Figure 12. Demag Comparator Threshold

versus T emperature

80

75

70

65

60

55

, DEMAG COMPARATOR THRESHOLD (mV)

50

–50 –25 0 25 50 75 100

demag–th

V

TA, AMBIENT TEMPERATURE (

VCC = 12 V

°

C)

50

PHASE (DEGREES)

–40

MOTOROLA ANALOG IC DEVICE DATA

7

MC44603

Figure 13. Current Sense Gain

versus T emperature

3.2

3.1

3.0

, CURRENT SENSE GAIN

2.9

VCS

A

2.8
–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (

VCC = 12 V

R

= 10 k

ref

CT = 820 pF

°

C)

Figure 15. Propagation Delay Current Sense

Input to Output versus Temperature

140

Figure 14. Thermal Resistance and Maximum

°

Power Dissipation versus P.C.B. Copper Length

100

80

60

40

20

0

, THERMAL RESISTANCE JUNCTION–TO–AIR ( C/W)

0

JA

θ

R

R

θ

JA

P

for TA = 70°C

D(max)

10 20 30 40 50

L, LENGTH OF COPPER (mm)

Printed circuit board heatsink example

2.0 oz

L

Copper

L

Graphs represent symmetrical layout

Figure 16. Startup Current versus V

0.35

0.30

3.0 mm

CC

5.0

4.0

3.0

2.0

1.0

0

, MAXIMUM POWER DISSIPATION (W)

D

P

120

100

PROPAGATION DELAY (ns)

80

–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (°C)

VCC = 12 V

R

= 10 k

ref

CT = 820 pF

Figure 17. Supply Current versus

Supply V oltage

16
14
12
10

8.0
TA = 25°C

6.0

R

= 10 k

, SUPPLY CURRENT (mA)

CC

I

ref

CT = 820 pF

4.0
VFB = 0 V

2.0

VCS = 0 V

0

2.0 4.0 6.0 8.0 10 12 14 16
VCC, SUPPLY VOLTAGE (V)

0.25

0.20

0.15

0.10

STAR TUP CURRENT (mA)

0.05
0

4.00 2.0 6.0
VCC, SUPPLY VOLTAGE (V)

8.0 10 12 14

R

= 10 k

ref

CT = 820 pF

Figure 18. Power Supply Zener V oltage

versus T emperature

21.5

21.0

20.5

20.0

, ZENER VOLTAGE (V)

Z

V

19.5

19.0
–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (

ICC = 25 mA

°

C)

8

MOTOROLA ANALOG IC DEVICE DATA

MC44603

Figure 19. Startup Threshold V oltage

versus T emperature

15.5

15.0

14.5
VCC Increasing VCC Decreasing

14.0

, STARTUP THRESHOLD VOLTAGE (V)

stup–th

13.5

V

–50 –25 0 25 50 75 100

°

TA, AMBIENT TEMPERATURE (

C)

Figure 21. Disable V oltage After Threshold

Turn–On (UVLO2) versus Temperature

7.8

Figure 20. Disable V oltage After Threshold

Turn–On (UVLO1) versus Temperature

9.50

9.25

, UVLO1 (V)

9.00

disable1

V

8.55

8.50
–50 –25 0 25 50 75 100

°

TA, AMBIENT TEMPERATURE (

C)

Figure 22. Protection Threshold Level on

V

versus T emperature

2.608.0

2.55

OVP

7.6

, UVLO2 (V)

7.4
VCC Decreasing

7.2

disable2

V

7.0

6.8

–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (°C)

Figure 23. Protection Level on V

CC

versus T emperature

18

R

= 10 k

ref

CT = 820 pF

Pin 6 Open

17

, PROTECTION LEVEL (V)

16.5

CC prot

V

16

–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (

°

C)

2.50

2.45

2.40

, PROTECTION THRESHOLD LEVEL (V)

2.35

2.30

OVP–th

V

–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (°C)

Figure 24. Propagation Delay (V

3.0

to V

µ

2.517.5

2.0

1.5

PROPAGATION DELAY ( s)

1.0
–50 –25 0 25 50 75 100

Low) versus Temperature

out

TA, AMBIENT TEMPERATURE (°C)

VCC = 12 V

> 2.58 V

OVP

VCC = 12 V
R

= 10 k

ref

CT = 820 pF

MOTOROLA ANALOG IC DEVICE DATA

9

MC44603

Figure 25. Standby Reference Current

µ

270
265
260
255
250
245
240

, STANDBY REFERENCE CURRENT (

235
230

R P Stby

–50 –25 0 25 50 75 100

IA)

versus T emperature

VR P

Stdby (Pin 12)

Voltage Increasing

TA, AMBIENT TEMPERATURE (

°

C)

, CURRENT SENSE THRESHOLD

CS–stby

V

Figure 26. Current Sense V oltage Threshold

Standby Mode versus T emperature

0.33

0.32

0.31

STANDBY MODE (V)

0.30
–50 –25 0 25 50 75 100

TA, AMBIENT TEMPERATURE (

VCC = 12 V
R

= 10 k

ref

CT = 820 pF
Pin 12 Clamped
at 1.0 V

°

C)

PIN FUNCTION DESCRIPTION

Pin Name Description

1 V
2 V

3 Output Peak currents up to 750 mA can be sourced or sunk, suitable for driving either MOSFET or Bipolar

4 Gnd The ground pin is a single return, typically connected back to the power source; it is used as control and

5 Foldback Input The foldback function provides overload protection. Feeding the foldback input with a portion of the V

6 Overvoltage

7 Current Sense

8 Demagnetization

9 Synchronization

10 C

11 Soft–Start/D

12 RP

13 E/A Out The error amplifier output is made available for loop compensation.
14 Voltage Feedback This is the inverting input of the Error Amplifier. It can be connected to the switching power supply output

15 RF
16 R

CC
C

Protection

Input

Detection

Input

T

Voltage–Mode

Standby

Standby

ref

max

This pin is the positive supply of the IC. The operating voltage range after startup is 9.0 to 14.5 V .
The output high state (VOH) is set by the voltage applied to this pin. With a separate connection to the

power source, it can reduce the effects of switching noise on the control circuitry.

transistors. This output pin must be shunted by a Schottky diode, 1N5819 or equivalent.

power ground.

voltage (1.0 V max) establishes on the system control loop a foldback characteristic allowing a smoother
startup and sharper overload protection. Above 1.0 V the foldback input is inactive.

When the overvoltage protection pin receives a voltage greater than 17 V , the device is disabled and
requires a complete restart sequence. The overvoltage level is programmable.

A voltage proportional to the current flowing into the power switch is connected to this input. The PWM
latch uses this information to terminate the conduction of the output buffer when working in a current
mode of operation. A maximum level of 1.0 V allows either current or voltage mode operation.

A voltage delivered by an auxiliary transformer winding provides to the demagnetization pin an indication
of the magnetization state of the flyback transformer. A zero voltage detection corresponds to complete
core saturation. The demagnetization detection ensures a discontinuous mode of operation. This
function can be inhibited by connecting Pin 8 to Gnd.

The synchronization input pin can be activated with either a negative pulse going from a level between

0.7 V and 3.7 V to Gnd or a positive pulse going from a level between 0.7 V and 3.7 V up to a level
higher than 3.7 V . The oscillator runs free when Pin 9 is connected to Gnd.

The normal mode oscillator frequency is programmed by the capacitor CT choice together with the R
resistance value. CT, connected between Pin 10 and Gnd, generates the oscillator sawtooth.

/

A capacitor, resistor or a voltage source connected to this pin limits the switching duty–cycle. This pin
can be used as a voltage mode control input. By connecting Pin 11 to Ground, the MC44603 can be
shut down.

A voltage level applied to the RP

turn into the reduced frequency mode of operation (i.e. standby mode). An internal hysteresis
comparator allows to return in the normal mode at a higher output power level.

through an optical (or other) feedback loop.

The reduced frequency or standby frequency programming is made by the RF

R

sets the internal reference current. The internal reference current ranges from 100 µA to 500 µA.

ref

This requires that 5.0 kΩ ≤ R

≤ 25 kΩ.

ref

pin determines the output power level at which the oscillator will

Standby

resistance choice.

Standby

CC

ref

10

MOTOROLA ANALOG IC DEVICE DATA

MC44603

Figure 27. Starting Behavior and Overvoltage Management

V

CC

VCC

prot

V

stup–th

V

disable1

V

disable2

V

ref

UVLO1

V

Pin 11

(Soft–Start)

V

OVP Out

Output

No–Take Over Loop Failure

Startup Restart

Normal Mode

>2.0

µ

s

I

CC

17 mA

0.3 mA

V

V

Demag In

V

Demag In

Output
(Pin 3)

Demag Out

Figure 28. Demagnetization

V

Demagnetization

Management

Demag Out

Oscillator

MOTOROLA ANALOG IC DEVICE DATA

Buffer Output

11

V

CC

V

stup–th

V

disable1

V

disable2

V

ref

UVLO1

V

Pin 11

(Soft–Start)

Output
(Pin 3)

MC44603

Figure 29. Switching Off Behavior

17 mA

0.3 mA

1.0 V

V

V

Demag Out

V

OSC

V

OSC prot

I

CC

V

CT

Stby

Figure 30. Oscillator

V

Demag Out

3.6 V

1.6 V

12

Synchronization

Input

C

T

Oscillator

V

Stby

V

OSC prot

V

OSC

MOTOROLA ANALOG IC DEVICE DATA

MC44603

V

CT

VCT low

V

Output

(Pin 3)

V

ref

OSC

3.6 V

1.6 V

V

CSS

+ 1.6 V

Figure 31. Soft–Start & D

Soft–Start

max

Internal Clamp

External Clamp

OPERA TING DESCRIPTION

Error Amplifier

A fully compensated Error Amplifier with access to the
inverting input and output is provided. It features a typical dc
voltage gain of 70 dB. The noninverting input is internally
biased at 2.5 V and is not pinned out. The converter output
voltage is typically divided down and monitored by the
inverting input. The maximum input bias current with the
inverting input at 2.5 V is –2.0 µA. This can cause an output
voltage error that is equal to the product of the input bias
current and the equivalent input divider source resistance.

The Error Amp output (Pin 13) is provided for external loop
compensation. The output voltage is offset by two diode
drops (≈ 1.4 V) and divided by three before it connects to the
inverting input of the Current Sense Comparator. This
guarantees that no drive pulses appear at the Output (Pin 3)
when Pin 13 is at its lowest state (VOL). The Error Amp
minimum feedback resistance is limited by the amplifier’s
minimum source current (0.2 mA) and the required output
voltage (VOH) to reach the current sense comparator’s 1.0 V
clamp level:

R

f(min)

3.0 (1.0 V))1.4 V

[

0.2 mA

+

22 k

W

Figure 32. Error Amplifier Compensation

+

Compensation

R

FB

R

C

f

Voltage

Feedback

Foldback

R1

f

R2

13

14

Input

Input

2.5 V

5

Amplifier

From Power Supply Output

Error

1.0 mA

2R

R

Gnd

Current Sense

Comparator

4

Current Sense Comparator and PWM Latch

The MC44603 can operate as a current mode controller or
as a voltage mode controller. In current mode operation, the
MC44603 uses the current sense comparator. The output
switch conduction is initiated by the oscillator and terminated
when the peak inductor current reaches the threshold level

MOTOROLA ANALOG IC DEVICE DATA

13

MC44603

established by the Error Amplifier output (Pin 13). Thus, the
error signal controls the peak inductor current on a
cycle–by–cycle basis. The Current Sense Comparator PWM
Latch ensures that only a single pulse appears at the Source
Output during the appropriate oscillator cycle.

The inductor current is converted to a voltage by inserting
the ground referenced sense resistor RS in series with the
power switch Q1.

This voltage is monitored by the Current Sense Input
(Pin 7) and compared to a level derived from the Error Amp
output. The peak inductor current under normal operating
conditions is controlled by the voltage at Pin 13 where:

V

Ipk[

The Current Sense Comparator threshold is internally
clamped to 1.0 V. Therefore, the maximum peak switch
current is:

I

pk(max)

Figure 33. Output T otem Pole

V

OSC prot

V

Demag Out

Thermal
Protection

Current Sense

Comparator

RSQ
R

PWM
Latch

Oscillator

The oscillator is a very accurate sawtooth generator that
can work either in free mode or in synchronization mode. In
this second mode, the oscillator stops in the low state and
waits for a demagnetization or a synchronization pulse to
start a new charging cycle.

• The Sawtooth Generation:

In the steady state, the oscillator voltage varies between
about 1.6 V and 3.6 V.

The sawtooth is obtained by charging and discharging an
external capacitor CT (Pin 10), using two distinct current
sources = I

charge

and I
connected to the charging current source (0.4 I
the discharge current source has to be higher than the
charge current to be able to decrease the CT voltage (refer
to Figure 35).

This condition is performed, its value being (2.0 I

normal working and (0.4 I

(Pin 13) – 1.4 V

[

UVLO

Substrate

discharge

ref

3R

S

1.0 V
R

S

V

C

14

R2

3

1N5819

Current
Sense

7

R3

C

. In fact, CT is permanently

+ 0.5 IF

in standby mode).

Stby

V

in

R

R

S

) and so,

ref

Q1

ref

) in

Figure 34. Oscillator

V

ref

0.4 I

ref

C

VOS prot

1.0 V
C

OSC Low

1.6 V

C

C

10

I

Regul

OSC High

OSC Regul

10

C

T

3.6 V

CT < 1.6 V

Discharge

R

Q

Disch

S

V

OSC prot

R

L

OSC

S

Q

Synchro

V
Out

01

I

Discharge

V

OSC

Demag

Figure 35. Simplified Block Oscillator

V

ref

I

Charge

0.4 I

10

C

T

ref

01

0: Discharge Phase
1: Charge Phase

I

Discharge

1.6 V

I

Regul

C

OSC Regul

Two comparators are used to generate the sawtooth. They
compare the CT voltage to the oscillator valley (1.6 V) and
peak reference (3.6 V) values. A latch (L

) memorizes the

disch

oscillator state.

In addition to the charge and discharge cycles, a third
state can exist. This phase can be produced when, at the end
of the discharge phase, the oscillator has to wait for a
synchronization or demagnetization pulse before restarting.
During this delay, the CT voltage must remain equal to the
oscillator valley value (]1.6 V). So, a third regulated current
source I
order to perfectly compensate the (0.4 I

controlled by C

Regul

OSC Regul

, is connected to CT in

) current source

ref

that permanently supplies CT.

The maximum duty cycle is 80%. Indeed, the on–time is
allowed only during the oscillator capacitor charge.

Consequently:

T

T

= CT x ∆V/I

charge

discharge

= CT x ∆V/I

charge

discharge

where:

T

is the oscillator charge time

charge

∆V is the oscillator peak–to–peak value

I

is the oscillator charge current

charge

and

T

discharge

I

discharge

is the oscillator discharge time

is the oscillator discharge current

14

MOTOROLA ANALOG IC DEVICE DATA

MC44603

So, as fS = 1 /(T
arrangement is not activated, the operating frequency can be
obtained from the graph in Figure 1.

NOTE: The output is disabled by the signal V
VCT is lower than 1.0 V (refer to Figure 30).

Synchronization and Demagnetization Blocks

To enable the output, the L
output must be low. Reset is activated by the L
during the discharge phase. T o restart, the L
(refer to Figure 34). To perform this, the demagnetization
signal and the synchronization must be low.

• Synchronization:

The synchronization block consists of two comparators
that compare the synchronization signal (external) to 0.7 and

3.7 V (typical values). The comparators’ outputs are
connected to the input of an AND gate so that the final output
of the block should be :

– high when 0.7 < SYNC < 3.7 V

– low in the other cases.

As a low level is necessary to enable the output,
synchronized low level pulses have to be generated on the
output of the synchronization block. If synchronization is not
required, the Pin 9 must be connected to the ground.

Figure 36. Synchronization

Oscillator

Output Buffer

charge

+ T

discharge

) when the Regul

OSC prot

latch complementary

OSC

has to be set

OSC

3.7 V

0.7 V

disch

Sync
9

when

output

A diode D has been incorporated to clamp the positive
applied voltages while an active clamping system limits the
negative voltages to typically –0.33 V. This negative clamp
level is sufficient to avoid the substrate diode switching on.

In addition to the comparator, a latch system has been
incorporated in order to keep the demagnetization block
output level low as soon as a voltage lower than 65 mV is
detected and as long as a new restart is produced (high level
on the output) (refer to Figure 38). This process prevents
ringing on the signal at Pin 8 from disrupting the
demagnetization detection. This results in a very accurate
demagnetization detection.

The demagnetization block output is also directly
connected to the output, disabling it during the
demagnetization phase (refer to Figure 33).

NOTE: The demagnetization detection can be inhibited by
connecting Pin 8 to the ground.

Figure 38. Demagnetization Block

Oscillator Output

Buffer

V

Demag Out

RSQ
Demag

C Dem

V

CC

Negative Active

Clamping System

65 mV

D

8

Standby

• Power Losses in a Classical Flyback Structure

• Demagnetization:

In flyback applications, a good means to detect magnetic
saturation of the transformer core, or demagnetization,
consists in using the auxiliary winding voltage. This voltage is:

– negative during the on–time,

– positive during the off–time,

– equal to zero for the dead–time with generally some

– ringing (refer to Figure 37).

That is why, the MC44603 demagnetization detection
consists of a comparator that can compare the auxiliary
winding voltage to a reference that is typically equal to
65 mV.

Figure 37. Demagnetization Detection

0.75 V

65 mV

–0.33 V

V

Pin 8

Zero Current

Detection

On–Time Off–Time Dead–Time

Figure 39. Power Losses in a Classical

Flyback Structure

Clamping
Network

R

S

Snubber

+

R

AC Line

ICL

V

in

+

R

startup

V

CC

MC44603

In a classical flyback (as depicted in Figure 39), the

standby losses mainly consist of the energy waste due to:

– the startup resistor R

startup

→

P

startup

– the consumption of the IC and

– the power switch control → P

– the inrush current limitation resistor R

ICL

– the switching losses in the power switch → P
– the snubber and clamping network → P

P

is nearly constant and is equal to:

startup

ǒ

(Vin–VCC)2ń

R

startup

Ǔ

→

P

control
ICL

SW
SN–CLN

MOTOROLA ANALOG IC DEVICE DATA

15

MC44603

P

only depends on the current drawn from the mains.

ICL

Losses can be considered constant. This waste of energy
decreases when the standby losses are reduced.

P
increased (each switching requires some energy to turn on
the power switch).

PSW and P
frequency.

Consequently, standby losses can be minimized by
decreasing the switching frequency as much as possible.

The MC44603 was designed to operate at a standby
frequency lower than the normal working one.

• Standby Power Calculations with MC44603

During a switching period, the energy drawn by the
transformer during the on–time to be transferred to the output
during the off–time, is equal to:

where:

– L is the transformer primary inductor,

– lpk is the inductor peak current.
Input power is labelled Pin:

where fS is the normal working switching frequency .
Also,

where RS is the resistor used to measure the power switch
current.

Thus, the input power is proportional to V
the internal current sense comparator input).

That is why the standby detection is performed by creating
a VCS threshold. An internal current source (0.4 x I
the threshold level by connecting a resistor to Pin 12.

As depicted in Figure 40, the standby comparator
noninverting input voltage is typically equal to (3.0 x VCS + VF)
while the inverter input value is (VR P

RP

ER

increases when the oscillator frequency is

control

SN–CLN

Pin+

are proportional to the switching

1

E

+

xLxI

2

0.5xLxI

Ipk+

2

pk

2

xf

pk

S

V

CS

R

S

CS

+ VF).

Stby

Figure 40. Standby

V

0.4 I

Stby

12

13

AmpOut

ref

refVref

0

0.6 I

1

2R
1R

ref

C

Stby

V

refVref

0.8 I

ref

10

I

Discharge/2IDischarge

C. S. Comparator

0.25
IF

Stby

Current Mirror X2

2

(VCS being

ref

Oscillator

Discharge

Current

V

ref

0.2 I

ref

) sets

The VCS threshold level is typically equal to

[(V

R P Stby

labelled P

)/3] and if the corresponding power threshold is

:

thL

P

+

0.5xLx

thL

V

RPStby

ǒ

3.0 R

2

Ǔ

xf

S

S

And as:

V

RPStby

R

PStby

+

R

PStby

+

R

RPStby

10.6 x RSxR

+

V

ref

x0.4xI

x0.4x

ref

Ǹ

x

ref

V

ref

R

ref

P

thL

Lxf

S

Thus, when the power drawn by the converter decreases,
VCS decreases and when VCS becomes lower than [V
x (VR P

)/3], the standby mode is activated. This results in

Stby

CS–th

an oscillator discharge current reduction in order to increase
the oscillator period and to diminish the switching frequency .
As it is represented in Figure 40, the (0.8 x I

) current

ref

source is disconnected and is replaced by a lower value one
(0.25 x IF

Where: IF

Stby

Stby

).

= V

ref/RF Stby

In order to prevent undesired mode switching when power
is close to the threshold value, a hysteresis that is
proportional to VR P
VCS threshold level that is equal to [2.5 x (VR P

is incorporated creating a second

Stby

Stby

)/3]. When
the standby comparator output is high, a second current
source (0.6 x I

) is connected to Pin 12.

ref

Finally, the standby mode function can be shown

graphically in Figure 41.

Figure 41. Dynamic Mode Change

P

in

f

S

Normal

Working

P

thH

P

thL

[(VR P

Stby

Standby

)/3] 2.5 x [(VR P

Stby

)/3]

f

Stby

V

CS

1

This curve shows that there are two power threshold

levels:

– the low one:

P

fixed by VR P

– the high one:

P

P

thH

thH

thL

+

+

(2.5)2xP

6.25 x P

thL

thL

Stby

x

x

f

f

Stby

f

Stby

f

S

S

16

MOTOROLA ANALOG IC DEVICE DATA

MC44603

Maximum Duty Cycle and Soft–Start Control

Maximum duty cycle can be limited to values less than
80% by utilizing the D
in Figure 42, the Pin 11 voltage is compared to the oscillator
sawtooth.

Figure 42. D

11

Z

Soft–Start

Capacitor

Figure 43. Maximum Duty Cycle Control

Voltage

D

max

Using the internal current source (0.4 I
voltage can easily be set by connecting a resistor to this pin.

If a capacitor is connected to Pin 1 1, the voltage increases
from 0 to its maximum value progressively (refer to Figure

44), thereby, implementing a soft–start. The soft–start
capacitor is discharged internally when the VCC (Pin 1)
voltage drops below 9.0 V.

Figure 44. Different Possible Uses of Pin 11

Pin 11

R Connected to Pin 11

I = 0.4 I

RI

ref

If no external component is connected to Pin 11, an
internal zener diode clamps the Pin 11 voltage to a value V
that is higher than the oscillator peak value, disabling
soft–start and maximum duty cycle limitation.

Foldback

As depicted in Fgure 32, the foldback input (Pin 5) can be
used to reduce the maximum VCS value, providing foldback
protection. The foldback arrangement is a programmable
peak current limitation.

If the output load is increased, the required converter peak
current becomes higher and VCS increases until it reaches its
maximum value (normally , VCS

Then, if the output load keeps on increasing, the system is
unable to supply enough energy to maintain the output
voltages in regulation. Consequently, the decreasing output
can be applied to Pin 5, in order to limit the maximum peak
current. In this way, the well known foldback characteristic
can be obtained (refer to Figure 45).

and soft–start control. As depicted

max

and Soft–Start

max

V

2.4 VD

ref

0.4 I

V

ref

C

Dmax

OSC

Output

Control

D

Oscillator

max

ref

V

Z

C C // R

max

V

Z

RI

= 1.0 V).

Output

Drive

Pin 11
V

CT

(Pin 10)

), the Pin 11

τ

= RC

Figure 45. Foldback Characteristic

V

V

O

Nominal

V

CC

V

disable2

out

New Startup

Sequence Initiated

Ipk

max

NOTE: Foldback is disabled by connecting Pin 5 to VCC.
Overvoltage Protection

The overvoltage arrangement consists of a comparator

that compares the Pin 6 voltage to V

(2.5 V) (refer to

ref

Figure 46).

If no external component is connected to Pin 6, the

comparator noninverting input voltage is nearly equal to:

2.0 k

ǒ

11.6 kW)

W

2.0 k

Ǔ

xV

W

The comparator output is high when:

2.0 k

ǒ

11.6 kW)

W

2.0 k

à

W

VCCw

Ǔ

xVCCw

17 V

A delay latch (2.0 µs) is incorporated in order to sense

overvoltages that last at least 2.0 µs.

If this condition is achieved, V

OVP out

, the delay latch
output, becomes high. As this level is brought back to the
input through an OR gate, V
the IC output) until V

is disabled.

ref

OVP out

remains high (disabling

Consequently, when an overvoltage longer than 2.0 µs is
detected, the output is disabled until VCC is removed and
then re–applied.

The VCC is connected after V

has reached steady state

ref

in order to limit the circuit startup consumption.

The overvoltage section is enabled 5.0 µs after the
regulator has started to allow the reference V

By connecting an external resistor to Pin 6, the threshold

Z

VCC level can be changed.

Figure 46. Overvoltage Protection

V

Enable

2.5 V
(V

ref

Delay

C

OVLO

)

ref

Out

In

µ

s

5.0

τ

In Out

(If V

the Output is Disabled)

τ

Delay

2.0

OVP out

External
Resistor

V

OVP

V

CC

T

2.5 V

0

11.6 k

6

2.0 k

Overload

CC

2.5 V

to stabilize.

ref

µ

s

= 1.0,

I

out

V

OVP out

MOTOROLA ANALOG IC DEVICE DATA

17

Undervoltage Lockout Section

Figure 47. VCC Management

V

ref enable

V

CC

1

1

V

disable2

7.5 V

V

disable1

9.0 V

C

0

C

UVLO1

startup

10

Startup

14.5 V

RF

Stby

Pin 15 Pin 16

Reference Block:

Voltage and Current

Sources Generator

(V

ref

UVLO1

(to Soft–Start)

MC44603

As depicted in Figure 47, an undervoltage lockout has
been incorporated to garantee that the IC is fully functional
before allowing system operation.

This block particularly , produces V
I

that is determined by the resistor R

ref

R

ref

Pin 16 and the ground:

V

+

ref

R

ref

I

ref

where V

ref

Another resistor is connected to the Reference Block:
R

that is used to fix the standby frequency .

F Stby

In addition to this, VCC is compared to a second threshold
level that is nearly equal to 9.0 V (V
generated to reset the maximum duty cycle and soft–start
block disabling the output stage as soon as VCC becomes

, I

ref

, ...)

lower than V

disable1

. In this way , the circuit is reset and made
ready for the next startup, before the reference block is
disabled (refer to Figure 29). Finally, the upper limit for the
minimum normal operating voltage is 9.4 V (maximum value
of V

disable1

((V

stup–th) min

) and so the minimum hysteresis is 4.2 V.

= 13.6 V).

The large hysteresis and the low startup current of the
MC44603 make it ideally suited for off–line converter
applications where efficient bootstrap startup techniques are
required.

(Pin 16 voltage) and

ref

connected between

ref

+

2.5 V (typically)

disable1

). UVLO1 is

18

MOTOROLA ANALOG IC DEVICE DATA

R15

5.6 k

R15
22 k

R17
22 k

R25

1.0 k

185 Vac

to

270 Vac

RFI

Filter

C8 2.2 nF

C9 1.0 nF

C10 1.0

C11

1.0 nF

R18
27 k

MC44603

Figure 48. 250 W Input Power Off–Line Flyback Converter with MOSFET Switch

R1

1.0/5.0 W

D1 ... D4

1N4007

Sync

9

10

µ

F

11

12

13

14

15

16

R19
10 k

C12

6.8 nF

1.0 nF/1000 V

R2

68 k/2.0 W

8

7

6

5

4

MC44603P

3

2

1

C4 ... C7

C16

100 pF

C15

1.0 nF

D15 1N5819

R10 10

C1
220

C2

µ

220

R12
27

R7 180 k

R8
15 k

R11 39

R12 22

C13
100 nF

µ

F

F

k

R9 1.0 k

D5

1N4934

L1

µ

H

1.0

1N4148

C14

4.7 nF

R20
22 k

5.0 W

C17
47 nF

M856

D6

R5

1.2 k

R6
150

MTP6N60E

R26

1.0 k

R14

D7

0.2

L

aux

MR856

2.2 nF

D12

C3

1.0 nF/1.0 kV

R3

4.7

L

p

C18

R13

1.0 k

MOC8101

M

MR856

MR852

MR852

MR852

TL431

C32 220 pF

D8

C30

µ

F

100

C29 220 pF

D9

1000

C26 220 pF

D10

1000

C23 220 pF

D11

1000

R21
10

33 nF

C21

µ

k

C20

22.5

100 µF

C27

µ

F

C25

µ

F

F

R24

270

C19

100 nF

L2

µ

C33

H

150 V/0.6 A

30 V/2.0 A

C28

0.1

14 V/2.0 A

C24

0.1 µF

7.0 V/2.0 A

C31

0.1 µF

µ

F

C22

0.1 µF

R23

147.5 k

D14
1N4733

R22

2.5 k

MOTOROLA ANALOG IC DEVICE DATA

19

MC44603

250 W Input Power Fly–Back Converter

185 V – 270 V Mains Range

MC44603P & MTP6N60E

Tests Conditions Results

Line Regulation

150 V

130 V
114 V

7.0 V

Load Regulation

150 V

Cross Regulation

150 V
Efficiency Vin = 220 Vac, Pin = 250 W 81%
Standby Mode

P input

Vin = 185 Vac to 270 Vac
F

= 50 Hz

mains

I

= 0.6 A

out

I

= 2.0 A

out

I

= 2.0 A

out

I

= 2.0 A

out

Vin = 220 Vac
I

= 0.3 A to 0.6 A

out

Vin = 220 Vac
I

(150 V) = 0.6 A

out

I

(30 V) = 0 A to 2.0 A

out

I

(14 V) = 2.0 A

out

I

(7.0 V) = 2.0 A

out

Vin = 220 Vac, P

= 0 W 3.3 W

out

10 mV
10 mV
10 mV
20 mV

50 mV

< 1.0 mV

Switching Frequency
Output Short Circuit P
Startup Pin = 250 W Vac = 160 V

out (max)

= 270 W Safe on all outputs

20 kHz fully stable

20

MOTOROLA ANALOG IC DEVICE DATA

185 Vac

to

270 Vac

RFI

Filter

MC44603

Figure 49. 125 W Input Power Off–Line Flyback Converter with Bipolar Switch

R1

1.0/5 W

D1 ... D4

1N4007

C4 ... C7

1.0 nF/1000 V

C1
100

µ

F

C3

1.0 nF/1.0 kV

R3

M

4.7

C32 220 pF

120 V/0.5 A

R15

5.6 k

R16
22 k

R17
22 k

R25

1.0 k

C9 1.0 nF

C10 1.0

C11

1.0 nF

R18
27 k

µ

F

10

11

12

13

14

15

16

R19
10 k

C12

6.8 nF

9

R2

68 k/2 W

MC44603P

100 pF

8

7

6

5

4

3

2

1

220

C16

R4

27

C15

1.0 nF
R7 180 k

R8
15 k

D15 1N5819

R10 10

R11 39

C13
100 nF

C2

µ

F

k

R9 1.0 k

D5

1N4934

V

CC

1N4148

C14

4.7 nF

D13 1N4728

C34 1.0 µF

D6

1.0

L1

µ

H

R5

1.2 k

R6
150

R14

0.33

L

aux

C18

2.2 nF

MJF18006

D12

MR856

R13

1.0 k

L

p

MOC8101

TL431

D8

MR856

C29 220 pF

D9

MR852

C26 220 pF

D10

MR852

C23 220 pF

D11

MR852

1000

R21

k

10

C20

33 nF

100 µF

1000

1000

C21

µ

F

100 nF

C30

C27

µ

C25

µ

R24

270

C19

C31

0.1 µF

28 V/1.0 A

F

F

C28

0.1 µF

15 V/1.0 A

C24

µ

F

0.1

8.0 V/1.0 A

C22

0.1 µF

R23

117.5 k

D14
1N4733

R22

2.5 k

MOTOROLA ANALOG IC DEVICE DATA

21

MC44603

125 W Input Power Fly–Back Converter

185 V – 270 V Mains Range

MC44603P & MJF18006

Tests Conditions Results

Line Regulation

120 V

128 V
115 V

8.0 V

Load Regulation

120 V

Cross Regulation

120 V
Efficiency Vin = 220 Vac, Pin = 125 W 85%
Standby Mode

P input

Vin = 185 Vac to 270 Vac
F

= 60 Hz

mains

I

= 0.5 A

out

I

= 1.0 A

out

I

= 1.0 A

out

I

= 1.0 A

out

Vin = 220 Vac
I

= 0.2 A to 0.5 A

out

Vin = 220 Vac
I

(120 V) = 0.5 A

out

I

(28 V) = 0 A to 1.0 A

out

I

(15 V) = 1.0 A

out

I

(8.0 V) = 1.0 A

out

Vin = 220 Vac, P

= 0 W 2.46 W

out

10 mV
10 mV
10 mV
20 mV

= 0.05 V

< 1.0 mV

Switching Frequency
Output Short Circuit P
Startup Pin = 125 W Vac = 150 V

out (max)

= 140 W Safe on all outputs

20 kHz fully stable

22

MOTOROLA ANALOG IC DEVICE DATA

MC44603

OUTLINE DIMENSIONS

P SUFFIX

PLASTIC PACKAGE

CASE 648–08

ISSUE R

–A–

916

B

18

F

C

S

SEATING

–T–

PLANE

H

G

D

16 PL

0.25 (0.010) T

K

M

A

J

M

DW SUFFIX

PLASTIC PACKAGE

CASE 751G–02

(SOP–16L)

–A–

16 9

–B– P8X

M

J

81

D16X

0.010 (0.25) B

M

S

A

T

0.010 (0.25)

S

F

C

–T–

G14X

K

SEATING
PLANE

M

ISSUE A

M

B

NOTES:

1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.

2. CONTROLLING DIMENSION: INCH.

3. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.

4. DIMENSION B DOES NOT INCLUDE MOLD FLASH.

5. ROUNDED CORNERS OPTIONAL.

DIM MIN MAX MIN MAX

L

M

R

X 45

_

A 0.740 0.770 18.80 19.55
B 0.250 0.270 6.35 6.85
C 0.145 0.175 3.69 4.44
D 0.015 0.021 0.39 0.53
F 0.040 0.70 1.02 1.77
G 0.100 BSC 2.54 BSC
H 0.050 BSC 1.27 BSC
J 0.008 0.015 0.21 0.38
K 0.110 0.130 2.80 3.30
L 0.295 0.305 7.50 7.74
M 0 10 0 10
S 0.020 0.040 0.51 1.01

NOTES:

1. DIMENSIONING AND TOLERANCING PER ANSI

Y14.5M, 1982.

2. CONTROLLING DIMENSION: MILLIMETER.

3. DIMENSIONS A AND B DO NOT INCLUDE MOLD

PROTRUSION.

4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER

SIDE.

5. DIMENSION D DOES NOT INCLUDE DAMBAR

PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN
EXCESS OF D DIMENSION AT MAXIMUM
MATERIAL CONDITION.

DIM MIN MAX MIN MAX

A 10.15 10.45 0.400 0.411
B 7.40 7.60 0.292 0.299
C 2.35 2.65 0.093 0.104
D 0.35 0.49 0.014 0.019

F 0.50 0.90 0.020 0.035

G 1.27 BSC 0.050 BSC

J 0.25 0.32 0.010 0.012
K 0.10 0.25 0.004 0.009
M 0 7 0 7

____

P 10.05 10.55 0.395 0.415
R 0.25 0.75 0.010 0.029

MILLIMETERSINCHES

____

INCHESMILLIMETERS

MOTOROLA ANALOG IC DEVICE DATA

23

MC44603

Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty , representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “T ypical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Affirmative Action Employer.

How to reach us:

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INTERNET: http://Design–NET.com 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298

24

◊

MOTOROLA ANALOG IC DEVICE DATA

MC44603/D

*MC44603/D*