Motorola MC44602 Datasheet

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The MC44602 is an enhanced high performance fixed frequency current mode controller that is specifically designed for off–line and high voltage dc–to–dc converter applications. This device has the unique ability of changing operating modes if the converter output is overloaded or shorted, offering the designer additional protection for increased system reliability. The MC44602 has several distinguishing features when compared to conventional current mode controllers. These features consist of a foldback amplifier for overload detection, valid load and demag comparators with a fault latch for short circuit detection, thermal shutdown, and separate high current source and sink outputs that are ideally suited for driving a high voltage bipolar power transistor, such as the MJE18002, MJE18004, or MJE18006.

Standard features include an oscillator with a sync input, a temperature compensated reference, high gain error amplifier, and a current sensing comparator. Protective features consist of input and reference undervoltage lockouts each with hysteresis, cycle–by–cycle current limiting, a latch for single pulse metering, and a flip–flop which blanks the output off every other oscillator cycle, allowing output deadtimes to be programmed from 50% to 70%. This device is manufactured in a 16 pin dual–in–line heat tab package for improved thermal conduction.

• Separate High Current Source and Sink Outputs Ideally Suited for

Driving Bipolar Power Transistors: 1.0 A Source, 1.5 A Sink

• Unique Overload and Short Circuit Protection

• Thermal Protection

• Oscillator with Sync Input

• Current Mode Operation to 500 kHz Output Switching Frequency

• Output Deadtime Adjustable from 50% to 70%

• Automatic Feed Forward Compensation

• Latching PWM for Cycle–By–Cycle Current Limiting

• Input and Reference Undervoltage Lockouts with Hysteresis

• Low Startup and Operating Current

Simplified Block Diagram

V

ref

16

Sync Input

RT/C

T

Compensation

Voltage Feedback–Input

7

8

1

3

V

ref

Undervoltage

Lockout

Oscillator

Error

Amplifier

Foldback Amplifier

5.0V

Reference

Flip Flop

and

Latching

PWM

Gnd 9

CC

Undervoltage

Lockout

Short Circuit

Detection

Thermal

V

CC

15

Load Detect Input

2

V

C

14

Source Output

11

Sink Output

10

Sink Ground

4, 5, 12, 13

Current Sense Input

6

Order this document by MC44602/D



HIGH PERFORMANCE

CURRENT MODE

CONTROLLER

SEMICONDUCTOR

TECHNICAL DATA

16

1

P2 SUFFIX

PLASTIC PACKAGE

CASE 648C

DIP (12 + 2 + 2)

PIN CONNECTIONS

RT/C

T

1

2

3

4

5

6

7

8

(Top View)

Compensation

Load Detect Input

Voltage Feedback Input

Sink Gnd

Current Sense Input

Sync Input

ORDERING INFORMATION

Operating

Device

MC44602 TA = –25 to 85°C DIP (12 + 2 + 2)

Temperature Range

16

V

ref

15

V

CC

14

V

C

13

Sink Gnd

12

11

Source Output

10

Sink Output

9

Gnd

Package

MOTOROLA ANALOG IC DEVICE DATA

 Motorola, Inc. 1996 Rev 0

1

MC44602

MAXIMUM RATINGS

Rating Symbol Value Unit

Total Power Supply and Zener Current (ICC + IZ) 30 mA Sink Ground Voltage

with Respect to Gnd (Pin 9)

Output Supply Voltage

with Respect to Sink Gnd (Pins 4, 5, 12, 13)

Output Current (Note 1)

Source

Sink Output Energy (Capacitive Load per Cycle) W 5.0 µJ Current Sense and Voltage Feedback Inputs V Sync Input

High State Voltage

Low State Reverse Current Load Detect Input Current I Error Amplifier Output Sink Current IEA Power Dissipation and Thermal Characteristics

Maximum Power Dissipation at TA = 25°C

Thermal Resistance, Junction–to–Air

Thermal Resistance, Junction–to–Case Operating Junction Temperature T Operating Ambient Temperature T

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

V

Sink(neg)

V

C

I

O(Source)

I

O(Sink)

in

V

IH

I

IL in

(Sink)

P

D

R

θJA

R

θJC

J

A

–5.0 V

20 V

1.0

1.5

–0.3 to 5.5 V

5.5

–20

–20 to +10 mA

10 mA

2.5 80 15

150 °C

–25 to +85 °C

A

V

mA

W

°C/W °C/W

ELECTRICAL CHARACTERISTICS (V

values TA = –25°C to +85°C [Note 3] unless otherwise noted.)

Characteristic

ERROR AMPLIFIER SECTION

Voltage Feedback Input (VO = 2.5V) V Input Bias Current (VFB = 2.5 V) I Open Loop Voltage Gain (VO = 2.0 V to 4.0 V) A Unity Gain Bandwidth

TJ = 25°C

TA = –25 to +85°C Power Supply Rejection Ratio (VCC = 10 V to 16 V) PSRR 65 70 – dB Output Current

Sink (VO = 1.5 V, VFB = 2.7 V)

Sink TJ = 25°C

Sink TA = –25 to +85°C

Source (VO = 5.0 V, VFB = 2.3 V)

Source TJ = 25°C

Source TA = –25 to +85°C

Output Voltage Swing

High State (I

Low State (I

NOTES: 2. Adjust VCC above the startup threshold before setting to 12V.

O(Source)

O(Sink)

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

= 0.5 mA, VFB = 2.3 V)

= 0.33 mA, VFB = 2.7 V)

and VC = 12 V [Note 2], RT = 10k, CT = 1.0 nF, for typical values TA = 25°C, for min/max

CC

Symbol Min Typ Max Unit

FB IB

VOL

BW

I

Sink

I

Source

V

OH

V

OL

2.45 2.5 2.65 V – –0.6 –2.0 µA

65 90 – dB

1.0

0.8

–

1.5

–

–2.0

6.0 –

1.4 –

5.0 –

–1.1

–

7.0

1.0

1.8

2.0

–

10

–

–0.2

–

1.1

MHz

mA

V

2

MOTOROLA ANALOG IC DEVICE DATA

MC44602

ELECTRICAL CHARACTERISTICS (V

and VC = 12 V [Note 2], RT = 10k, CT = 1.0 nF, for typical values TA = 25°C, for min/max

CC

values TA = –25°C to +85°C [Note 3] unless otherwise noted.)

Characteristic

Symbol Min Typ Max Unit

OSCILLATOR SECTION

Frequency

TJ = 25°C

TA = –25°C to +85°C Frequency Change with Voltage (VCC = 12 V to 18 V) ∆f Frequency Change with Temperature ∆f Oscillator Voltage Swing (Peak–to–Peak) V Discharge Current (V

TJ = 25°C

OSC

= 3.0 V)

TA = –25°C to +85°C

f

OSC

/∆V – 0.1 0.2 %/V

OSC

/∆T – 0.05 – %/°C

OSC

OSC(pp) I

dischg

168 160

180

–

192 200

1.3 1.6 – V

6.5

6.0

10

–

14

13.5

Sync Input Threshold Voltage

High State

Low State Sync Input Resistance

TJ = 25°C

TA = –25°C to +85°C

V

IH

V

IL

R

in

2.5

1.0

6.5

6.0

2.8

1.3

10

3.2

1.7

13.5

–

18

REFERENCE SECTION

Reference Output Voltage (IO = 1.0 mA) V Line Regulation (VCC = 12 V to 18 V) Reg Load Regulation (IO = 1.0 mA to 20 mA) Reg T emperature Stability T Total Output Variation over Line, Load and Temperature V Output Noise Voltage (f = 10 Hz to 10 kHz, TJ = 25°C) V

ref

line load S

ref

n

4.7 5.0 5.3 V – 1.0 10 mV – 3.0 15 mV – 0.2 – mV/°C

4.65 – 5.35 V – 50 – µV

Long Term Stability (TA = 125°C for 1000 Hours) S – 5.0 – mV Output Short Circuit Current

TJ = 25°C TA = –25°C to +85°C

I

SC

–

–70

–130

–

–180

CURRENT SENSE SECTION

Current Sense Input Voltage Gain (Notes 4 & 5)

TJ = 25°C

TA = –25°C to +85°C Maximum Current Sense Input Threshold (Note 4) V Input Bias Current I Propagation Delay (Current Sense Input to Sink Output) t

A

V

th

IB

PLH(in/out)

2.85

2.7

3.0 –

3.2

3.15

0.9 1.0 1.1 V – –4.0 –10 µA – 100 150 ns

UNDERVOLTAGE LOCKOUT SECTIONS

Startup Threshold (VCC Increasing) V Minimum Operating Voltage After Turn–On (VCC Decreasing) V Reference Undervoltage Threshold (V

NOTES: 2.Adjust VCC above the startup threshold before setting to 12V.

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

4.This parameter is measured at the latch trip point with IFB = –5.0

5.Comparator gain is defined as AV =

Decreasing) V

ref

µA, refer to Figure 9.

∆V Compensation

∆V Current Sense Input

th

CC(min)

(UVLO) 3.0 3.35 3.7 V

ref

13 14.1 15 V

9.0 10.2 11 V

kHz

mA

V

kΩ

mA

V/V

MOTOROLA ANALOG IC DEVICE DATA

3

MC44602

Ä

ÄÄÄÄ

ELECTRICAL CHARACTERISTICS

(V

and VC = 12 V [Note 2], RT = 10k, CT = 1.0 nF, for typical values TA = 25°C, for min/max

CC

values TA = –25°C to +85°C [Note 3] unless otherwise noted.)

Characteristic

Symbol Min Typ Max Unit

OUTPUT SECTION

Output Voltage (TA = 25°C)

Low State (I

Low State (I Low State (I

High State (I

Output Voltage with UVLO Activated (VCC = 6.0 V, I Output Voltage Rise T ime (CL = 1.0 nF, TJ = 25°C) t Output Voltage Fall T ime (CL = 1.0 nF, TJ = 25°C) t

Sink

= 1.0A)

Sink

= 1.5 A)

Sink

Source Source Source

= 100 mA)

= 50 mA) = 0.5 A) = 0.75 A)

= 1.0 mA) V

Sink

V

OL

(VCC–VOH)

OL(UVLO)

r

f

PWM SECTION

Duty Cycle

Maximum Minimum

DC

(max)

(min)

TOTAL DEVICE

Power Supply Current

Startup (VCC = 5 V)

I

CC

Operating (Note 2)

TJ = 25° C TA = –25°C to +85° C

Power Supply Zener Voltage (ICC = 25 mA) V

Z

OVERLOAD AND SHORT CIRCUIT PROTECTION

Foldback Amplifier Threshold (Figures 9,10) ∆V Load Detect Input

Valid Load Comparator Threshold (V Demag Comparator Threshold (V Propagation Delay (Input to Sink or Source Output)

Pin 2

Decreasing)

Pin 2

Increasing)

Input Resistance

NOTES: 2. Adjust VCC above the startup threshold before setting to 12V.

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

FB

V

th(VL)

V

th(Demag)

t

PLH(in/out)

R

in

(VFB–100) (VFB–200) (VFB–300) mV

– – –

0.6

1.8

2.1

1.4

1.7

1.8

0.3

2.0

2.6

1.7

2.0

2.2 – 0.1 1.1 V – 50 150 ns – 50 150 ns

46

–

48

–

0

50

–

10

0.2

17

0.5

20

–

22

18 20 23 V

2.0 50

–

12

2.5 88

1.1 18

3.0

120

1.6 30

V

%

mA

V

mV

µS kΩ

80 50

30

Ω

20

CT=5.0 nF

10

8.0 CT=10 nF

5.0

3.0

, TIMING RESISTOR (k )

VCC = 12 V

T

R

2.0

TA = 25

°

C

Note: Output switches at one–half the oscillator frequency.

1.0

0.8

4

Figure 1. Timing Resistor

versus Oscillator Frequency

CT=500 pF

CT=2.0 nF

f

, OSCILLAT OR FREQUENCY (Hz)

OSC

CT=100 pF

CT=200 pF

CT=1.0 nF

1.0 M500 k200 k100 k50 k20 k10 k

75

1. CT = 10 nF

2. CT = 5.0 nF

3. CT = 2.0 nF

70

4. CT = 1.0 nF

5. CT = 500 pF

6. CT = 100 pF

65

60

55

% DT, PERCENT OUTPUT DEADTIME

50

Figure 2. Output Deadtime

versus Oscillator Frequency

Note: Output switches at one–half the oscillator frequency .

5

4

3

2

1

VCC = 12 V TA = 25

20 k 50 k 200 k 500 k

f

, OSCILLAT OR FREQUENCY (Hz)

OSC

MOTOROLA ANALOG IC DEVICE DATA

6

°

C

1.0 M100 k10 k

MC44602

12

11

10

9.0

, DISCHARGE CURRENT (mA)

8.0

dischg

I

7.0

2.55 V

–55

Figure 3. Oscillator Discharge Current

versus T emperature

VCC = 12 V V

= 3.0 V

OSC

–25 0 25 50 75 100 125

°

TA, AMBIENT TEMPERATURE (

C)

Figure 5. Error Amp Small Signal

Transient Response

VCC = 12 V AV = –1.0

°

C

TA = 25

5.0

4.0

3.0

2.0

, OSCILLAT OR VOLTAGE SWING (V)V

1.0

OSC

3.0 V

0

–55

Figure 4. Oscillator V oltage Swing

versus T emperature

VCC = 12 V RT = 10 k CT = 1.0 nF

Peak Voltage

Valley Voltage

–25 0 25 50 75 100 125

TA, AMBIENT TEMPERATURE (

°

C)

Figure 6. Error Amp Large Signal

Transient Response

VCC = 12 V AV = –1.0

°

C

TA = 25

2.5 V

2.45 V

Figure 7. Error Amp Open Loop Gain and

100

80

60

40

20

, OPEN LOOP VOL TAGE GAIN (dB)

0

VOL

A

–20

µ

t, TIME (0.5

s/DIV) t, TIME (1.0 µs/DIV)

Phase versus Frequency

VCC = 12 V VO = 2.0 V to 4.0 V RL = 100 k

°

C

Gain

1.0 k 10 k 100 k 1.0 M f, FREQUENCY (Hz)

TA = 25

Phase

2.5 V

20 mV/DIV

2.0 V

200 mV/DIV

Figure 8. Current Sense Input Threshold versus

Error Amp Output Voltage

0

30

60

90

120

150

180

10 M0.1 k

1.2

1.0 TA = 125°C

0.8

0.6

TA = 25°C

0.4

EXCESS PHASSE (DEGREES)

0.2

, CURRENT SENSE INPUT THRESHOLD (V)V

th

0

1.0 3.0 5.0 7.0

0

2.0 4.0 6.0

VO, ERROR AMP OUTPUT VOLTAGE (V)

TA = –40°C

VCC = 12 V

MOTOROLA ANALOG IC DEVICE DATA

5

MC44602

2.6

2.2

1.8

, INPUT VOLTAGE (V)

in

V

1.4

1.0 –500

200

160

120

Figure 9. V oltage Feedback Input,

V oltage versus Current

V

= 1.0 V

Clamp

VCC = 12 V

°

C

TA = 25

V

= 0.3 V

Clamp

V

Clamp

–400 –300 –200 –100 0

Iin, INPUT CURRENT (

V

= 0.1 V

Clamp

= 0.7 V

µ

A)

V

Clamp

= 0.5 V

Figure 11. Reference Short Circuit Current

versus T emperature

VCC = 12 V

≤

0.1

RL

Figure 10. V oltage Feedback Input

versus Current Sense Clamp Level

2.6 VCC = 12 V

2.2

TA = 125°C

1.8

, INPUT VOLTAGE (V)

in

1.4

V

1.0

TA = 25°C

TA = –55°C

0

0.2 0.4 0.6 0.8 1.0 V

, CURRENT SENSE CLAMP LEVEL (V)

Clamp

Figure 12. Reference Line and Load

Regulation versus T emperature

3.0

Ω

2.0

1.0

–1.0

Line Regulation

0

VCC = 12 V to 18 V I

= 0 mA

ref

80

, REFERENCE SHORT CIRCUIT CURRENT (mA)

SC

40

I

–55

–25 0 25 50 75 100 125

Figure 13. Reference V oltage Change

0

–5.0

–10

–15

–20

, REFERENCE VOLTAGE CHANGE (mV)

–25

ref

V

∆

–30

0

VCC = 12 V

30 60 90 120 150 180

I

ref

°

TA, AMBIENT TEMPERATURE (

C)

versus Source Current

TA = –55°C

TA = 25°C

TA = 125°C

, REFERENCE SOURCE CURRENT (mA)

–2.0

Load Regulation

–3.0

VCC = 12 V I

, REFERENCE VOLTAGE CHANGE (mA)

–4.0

ref

V

∆

–5.0

= 1.0 mA to 20 mA

ref

–55

–25 0 25 50 75 100 125

TA, AMBIENT TEMPERATURE (

Figure 14. Thermal Resistance and Maximum

Power Dissipation versus P.C.B. Copper Length

°

100

80

60

40

20

, THERMAL RESISTANCE JUNCTION T O AIR ( C/W)

JA

0

θ

0

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

°

C)

5.0

4.0

3.0 mm

3.0

2.0

1.0

0

, MAXIMUM POWER DISSIPATION (W)

D

P

6

MOTOROLA ANALOG IC DEVICE DATA