MOTOROLA UA78S40PV, UA78S40PC, UA78S40MC Datasheet
Device
Temperature
Range
Package
µ
SEMICONDUCTOR
TECHNICAL DATA
UNIVERSAL
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
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
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 kΩ to Gnd, 1.0 V ≤ VO ≤ 2.5 V)
A
VOL
+ 25 250 – V/mV
Voltage Gain – (TA = 25°C)
(RL = 2.0 kΩ 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
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