Datasheet UA78S40PV, UA78S40PC, UA78S40MC Datasheet (MOTOROLA)

Page 1
Device
Temperature
Range
Package
µ

SEMICONDUCTOR
TECHNICAL DATA
SWITCHING REGULATOR
SUBSYSTEM
ORDERING INFORMATION
µA78S40PC µA78S40PV
TA = 0° to +70°C
TA = – 40° to +85°C
Plastic Plastic
PIN CONNECTIONS
Order this document µA78S40/D
P SUFFIX
PLASTIC PACKAGE
CASE 648
11
5
2
1
9
10
12
13
14
15
16
8
7
6
4
3
(Top View)
Diode Anode
Reference
Inv. Input
Noninv.
VCC Op Amp
Op Amp Output
Switch Emitter
Diode Cathode
Op
Amp
Comparator Noninv. Input
Comparator Inv. Input
Ground
Timing Capacitor
V
CC
Ipk Sense
Driver Collector
Switch Collector
1
MOTOROLA ANALOG IC DEVICE DATA
   
The µA78S40 is a switching regulator subsystem, consisting of a temperature compensated voltage reference, controlled–duty cycle oscillator with an active current limit circuit, comparator, high–current and high–voltage output switch, capable of 1.5 A and 40 V, pinned–out power diode and an uncommitted operational amplifier, which can be powered up or down independent of the IC supply. The switching output can drive external NPN or PNP transistors when voltages greater the 40 V, or currents in excess of 1.5 A, are required. Some of the features are wide–supply voltage range, low standby current, high efficiency and low drift. The µA78S40 is available in commercial (0° to + 70°C), and automotive (–40° to + 85°C) temperature ranges.
Some of the applications include use in step–up, step–down, and inverting regulators, with extremely good results obtained in battery– operated systems.
Output Adjustable from 1.25 V to 40 V
Peak Output Current of 1.5 A Without External Transistor
80 dB Line and Load Regulation
Operation from 2.5 V to 40 V Supply
Low Standby Current Drain
High Gain, High Output Current, Uncommitted Op Amp
Simplified Block Diagram
C
T
I
pk
Oscilator
– +
Comp.
– +
Op
1.25V
Reference
SRQ
170
8
(Bottom View)
Ref
Output
Output
9
D1
Inv
Input
Noninv
Input
V
CC
Op Amp
Switch Emitter
Diode
Anode
Diode
Cathode
Noninv.
Input
Inv.
Input
Gnd
Timing
Capacitor
V
CC
I
pk
Sense
Driver
Collector
Switch
Collector
7654321
10 11 12 13 14 15 16
Amp
Motorola, Inc. 1996 Rev 1
Page 2
µA78S40
2
MOTOROLA ANALOG IC DEVICE DATA
MAXIMUM RATINGS
Rating Symbol Value Unit
Power Supply Voltage V
CC
40 V Op Amp Power Supply Voltage VCC (Op Amp) 40 V Common Mode Input Range
(Comparator and Op Amp)
V
ICR
–0.3 to V
CC
V
Differential Input Voltage (Note 2) V
ID
± 30 V Output Short Circuit Duration (Op Amp) Continuous – Reference Output Current I
ref
10 mA Voltage from Switch Collectors to Gnd 40 V Voltage from Switch Emitters to Gnd 40 V Voltage from Switch Collectors to Emitter 40 V Voltage from Power Diode to Gnd 40 V Reverse–Power Diode Voltage V
DR
40 V Current through Power Switch I
SW
1.5 A
Current through Power Diode I
D
1.5 A
Power Dissipation and Thermal Characteristics:
Plastic Package (TA = + 25°C)
Derate above + 25°C (Note 1)
P
D
1/R
θJA
1500
14
mW
mW/°C
Storage Temperature Range T
stg
–65 to + 150 °C
Operating Temperature Range
µA78S40V µA78S40C
T
A
–40 to +85
0 to +70
°C
NOTES: 1. T
low
= –40° for µA78S40PV T
high
= +85° for µA78S40PV
=0° for µA78S40PC = +70° for µA78S40PC
2.For supply voltages less than 30 V the maximum differential input voltage (Error Amp and Op Amp) is equal to the supply voltage.
ELECTRICAL CHARACTERISTICS (V
CC
= VCC (Op Amp) 5.0 V, TA = T
low
to T
high
, unless otherwise noted.)
Characteristic Symbol Min Typ Max Unit
GENERAL
Supply Voltage V
CC
2.5 40 V
Supply Current (Op Amp VCC, disconnected)
(VCC = 5.0 V) (VCC = 40 V)
I
CC
– –
1.8
2.3
3.5
5.0
mA
Supply Current (Op Amp VCC, connected)
(VCC = 5.0 V) (VCC = 40 V)
I
CC
– –
– –
4.0
5.5
mA
REFERENCE
Reference Voltage
(I
ref
= 1.0 mA)
V
ref
1.180 1.245 1.310 V
Reference Voltage Line Regulation
(3.0 V VCC≤ 40 V, I
ref
= 1.0 mA, TA = 25°C)
Reg
line
0.04 0.2 mV/V
Reference Voltage Load Regulation
(1.0 mA I
ref
10 mA, TA = 25°C)
Reg
load
0.2 0.5 mV/mA
Page 3
µA78S40
3
MOTOROLA ANALOG IC DEVICE DATA
ELECTRICAL CHARACTERISTICS (V
CC
= VCC (Op Amp) 5.0 V, TA = T
low
to T
high
, unless otherwise noted.)
Characteristic
Symbol Min Typ Max Unit
OSCILLAT OR
Charging Current (TA = 25°C)
(VCC = 5.0 V)
(VCC = 40 V)
I
chg
20 20
– –
50 70
µA
Discharging Current (TA = 25°C)
(VCC = 5.0 V)
(VCC = 40 V)
I
dis
150 150
– –
250 350
µA
Oscillator Voltage Swing (TA = 25°C)
(VCC = 5.0 V)
V
osc
0.5 V
Ratio of Charge/Discharge Time t
chg/tdis
6.0
CURRENT LIMIT
Current–Limit Sense Voltage (TA = 25°C)
(VCC – V
lpk
Sense)
V
CLS
250 350 mV
OUTPUT SWITCH
Output Saturation Voltage 1
(ISW = 1.0 A, Pin 15 tied to Pin 16)
V
sat1
0.93 1.3 V
Output Saturation Voltage 2
(ISW = 1.0 A, I15 = 50 mA)
V
sat2
0.5 0.7 V
Output Transistor Current Gain (TA = 25°C)
(IC = 1.0 A, VCE = 5.0 V)
h
FE
70
Output Leakage Current (TA = 25°C)
(VCE = 40 V)
I
C(off)
10 nA
POWER DIODE
Forward Voltage Drop (ID = 1.0 A) V
D
1.25 1.5 V
Diode Leakage Current (TA = 25°C) (VDR = 40 V) I
DR
10 nA
COMPARATOR
Input Offset Voltage (VCM = V
ref
) V
IO
1.5 15 mV
Input Bias Current (VCM = V
ref
) I
IB
35 200 nA
Input Offset Current (VCM = V
ref
) I
IO
5.0 75 nA
Common Mode Voltage Range (TA = 25°C) V
ICR
0 VCC – 2.0 V
Power–Supply Rejection Ratio (TA = 25°C)
(3.0 VCC 40 V)
PSRR 70 96 dB
OUTPUT OPERATION AMPLIFIER
Input Offset Voltage (VCM = 2.5 V) V
IO
4.0 15 mV
Input Bias Current (VCM = 2.5 V) I
IB
30 200 nA
Input Offset Current (VCM = 2.5 V) I
IO
5.0 75 nA
Voltage Gain + (TA = 25°C)
(RL = 2.0 k to Gnd, 1.0 V VO 2.5 V)
A
VOL
+ 25 250 V/mV
Voltage Gain – (TA = 25°C)
(RL = 2.0 k to VCC (Op Amp), 1.0 V VO 2.5 V)
A
VOL
25 250 V/mV
Common Mode Voltage Range (TA = 25°C) V
ICR
0 VCC – 2.0 V
Common Mode Rejection Ratio (TA = 25°C)
(VCM = 0 V to 3.0 V)
CMRR 76 100 dB
Power–Supply Rejection Ratio (TA = 25°C)
(3.0 V VCC (Op Amp) 40 V)
PSRR 76 100 dB
Output Source Current (TA = 25°C) I
Source
75 150 mA
Output Sink Current (TA = 25°C) I
Sink
10 35 mA Slew Rate (TA = 25°C) SR 0.6 V/µs Output Low Voltage (TA = 25°C, IL = –5.0 mA) V
OL
1.0 V
Output High Voltage (TA = 25°C, IL = 50 mA) V
OH
VCC(Op Amp)
– 3.0
V
Page 4
µA78S40
4
MOTOROLA ANALOG IC DEVICE DATA
Figure 1. Output Switch On/Off Time
versus Oscillator Timing Capacitor
Figure 2. Standby Supply Current
versus Supply Voltage
Figure 3. Emitter–Follower Configuration
Output Switch Saturation Voltage
versus Emitter Current
CT, OSCILLATOR TIMING CAPACITOR (nF)
0.1 1.0 10 100
, OUTPUT SWITCH ON-OFF TIME ( s)
µ
on-off
t
VCC = 5.0 V I
pk(sense)
= V
CC Pin 10 = Gnd Pin 9 = V
ref
t
on
t
off
VCC, SUPPLY VOLTAGE (V)
0 5.0 10 15 20 25 30 35 40
, SUPPLY CURRENT (mA)
CC
I
CT = 0.001 µF I
pk(sense)
= V
CC
Pin 3 = Gnd
IE, EMITTER CURRENT (A)
, SATURATION VOLTAGE (V)
CE(sat)
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
V
VCC = 5.0 V Pins 14, 15, 16 = V
CC
Pins 10, 12 = Gnd Pin 9 = V
ref
IC, COLLECTOR CURRENT (A)
, SATURATION VOLTAGE (V)
CE(sat)
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
V
VCC = 5.0 V Pin 14 = V
CC
Pins 3, 10, 12 = Gnd Pin 9 = V
ref
Darlington Connection
Figure 4. Common–Emitter Configuration
Output Switch Saturation Voltage
versus Collector Current
1000
100
10
1.0
3.2
2.4
1.6
0.8
0
1.6
1.5
1.4
1.3
1.2
1.1
1.0
1.2
1.0
0.8
0.6
0.4
0.2
0
Forced Beta = 20
Page 5
µA78S40
5
MOTOROLA ANALOG IC DEVICE DATA
C
T
I
pk
Oscilator
– +
Comp.
– +
Op
Amp
1.25V
Reference
SRQ
170
12345678
9 10111213141516
D1
V
out
5.0V/500mA
*
L
470
+
C
O
R2
3.6k
R1
1N5822
+
100
C
T
* Use external rectifier to increase circuit efficiency
1.2k
V
in
25V
470
pF
R
SC
0.33
220
µ
H
V
CC
Figure 5. Step–Down Converter
C
T
I
pk
Oscilator
– +
Comp.
– +
Op
Amp
1.25V
Reference
SRQ
170
12345678
9 10111213141516
D1
V
out
28V/175mA
*
150
+
C
O
R2
47k
R1
1N5822
+
100
C
T
* Use external rectifier to increase circuit efficiency
22k
V
in
12V
1500
pF
R
SC
0.22
V
CC
Figure 6. Step–Up Converter
170µH
L
180
Page 6
µA78S40
6
MOTOROLA ANALOG IC DEVICE DATA
C
T
I
pk
Oscilator
– +
Comp.
– +
Op
Amp
1.25V
Reference
SRQ
170
12345678
9 10111213141516
D1
R1
1.5k
1N5822
+
100
C
T
V
in
15V
1800
pF
R
SC
0.30 50
µ
HL
100
V
out
–15V/500mA
100
+
C
O
R2
18k
V
CC
270
D45H8
Figure 7. Inverting Converter
Design Formula Table
f
min
V
in(min)
V
sat
Calculation Step–Down Step–Up Inverting
t
on
t
off
V
out
+ V
F
V
out
– VF V
in(min)
V
out
+ V
F
V
in(min)
– V
sat
– V
out
V
in(min)
– V
sat
(ton + t
off
) max
f
min
I
f
min
I
I
C
T
4 x 10 5 t
on
4 x 10 5 t
on
4 x 10 5 t
on
I
pk(switch)
2 I
out(max)
ton – t
off
t
off
ton + t
off
t
off
2 I
out(max)
2 I
out(max)
R
SC
0.33 0.33 0.33
I
pk(switch)
I
pk(switch)
I
pk(switch)
L
(min)
V
in(min)
– V
sat
– V
out
V
in(min)
– V
sat
V
in(min)
– V
sat
t
on(max)
t
on(max)
t
on(max)
I
pk(switch)
I
pk(switch)
I
pk(switch)
C
O
I
pk(switch)
(ton + t
off
)I
out ton
I
out ton
8 V
ripple(pp)
V
ripple
V
ripple
V
sat
= Saturation voltage of the output switch. VF = Forward voltage drop of the ringback rectifier.
≈≈
The following power supply characteristics must be chosen:
– Nominal input voltage. If this voltage is not constant, then use V
in(max)
for step–down and V
in(min)
for step–up and inverting convertor.
– Desired output voltage: V
out
= 1.25
– Desired output current. – Minimum desired output switching frequency at the selected values for Vin and IO. – Desired peak–to–peak output ripple voltage. In practice, the calculated value will need to be increased due to the capacitor’s equivalent series
resistance and board layout. The ripple voltage should be kept to a low value since it will directly effect the line and load regulation.
See Application Note AN920 for further information
for step–down and step–up: for inverting.
ǒ
1
)
R
2
R
1
Ǔ
V
out
+
1.25 R
2
R
1
V
in
V
out
I
out
f
min
V
ripple(pp)
Page 7
µA78S40
7
MOTOROLA ANALOG IC DEVICE DATA
OUTLINE DIMENSIONS
P SUFFIX
PLASTIC PACKAGE
CASE 648–08
ISSUE R
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.
–A–
B
F
C
S
H
G
D
J
L
M
16 PL
SEATING
18
916
K
PLANE
–T–
M
A
M
0.25 (0.010) T
DIM MIN MAX MIN MAX
MILLIMETERSINCHES
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
____
Page 8
µA78S40
8
MOTOROLA ANALOG IC DEVICE DATA
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.
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µA78S40/D
*uA78S40/D*
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