GM317L
3-TERMINAL 100mA
ADJUSTABLE REGULATOR
Description
The GM317L is an adjustable 3-terminal positive
voltage regulator capable of supplying 100mA
over an output voltage range of 1.2 V to 37 V.
This voltage regulator is exceptionally easy to
use and requires only two external resistors to
set the output voltage. Further, it employs
internal current limiting, thermal shutdown and
safe area compensation, making it essentially
blow out proof.
GM317L offers full overload protection. Included
on the chip current limit, thermal overload
protection, and safe-area protection. Normally,
no capacitors is needed unless the device is
situated far from the input filter capacitors in
which case an input bypass is needed. An
optional output capacitor can added to improve
transient response.
Features
Output current up to 100mA
Output Voltages 1.2V to 37V
Internal thermal overload protection
Internal short circuit current limiting
Output transistor safe area
compensation
Floating operation for high voltage
applications
Available in TO-92 and SO8 packages
Applications
Voltage Regulators
Power Supplies
Current Regulators
Switching Regulators
Current Limiter
Constant Current Battery Charger
Current Limited Charger
Typical Application Circuit
L
V
IN
V
IN
GM317L
V
OUT
ADJ
I
ADJ
V
OUT
R1
240Ω
C
O
**
1µF
C
IN
*
0.1µF
R2
* C
IN
is required if regulator is located an appreciable distance from power supply filter.
**C
O i
s not needed for stability, however, it improve transient response.
V
OUT
= 1.25V (1+
R2
) + I
ADJ
R2
R1
Since I
ADJ
is controlled to less than 100µA, the error associated with this term is negligible
in most applications.
1
GM317L
V2.01
GM317L
3-TERMINAL 100mA
ADJUSTABLE REGULATOR
Marking Information and Pin Configurations (Top View)
TO 92
SO 8
317LG
AYWW
1. V
IN
2. V
OUT
3. V
OUT
8. NC
7. V
OUT
6. V
OUT
5. NC
GM317LG
VAYWW
Adj 1
2
3 V
IN
4. Adj
V
OUT
G: Green Product
A: Assembly / Test site code
Y: Year
WW: Week
Ordering Information
Ordering Number
GM317LT92BG
GM317LT92RLG
GM317LS8RG
Adj
V
OUT
Package
TO 92
TO 92
SO 8
Shipping
1,000 Units/ESD Bag
2,000 Units/Ammo Pack (Tape)
2500 Units / Reel
GM317L
V2.01
2
GM317L
3-TERMINAL 100mA
ADJUSTABLE REGULATOR
Absolute Maximum Ratings
PARAMETER
Input Voltage, V
I
Input to Output Differential Voltage, V
I
– V
O
Operating Junction Temperature
Storage Temperature
Lead Temperature 1.6mm (1/6 inch) from case for 10 seconds
T
J
T
stg
RATINGS
41
40
0 to 125
- 60 to 150
260
UNITS
V
V
°C
°C
°C
Recommended Operating Conditions
PARAMETER
Output Current, I
O
Operating Virtual Junction Temperature, T
J
Min
10
0
Max
100
125
Unit
mA
°C
Block Diagram
IN
Q14
R20
300K
Q20A
Q20B
Q20C
Q20D
Q20E
R9
300
Q1
Q2
Q3
Q24
Q21
Q22
R1
200
C3
20pF
R2
500
Q23
R18
30K
C1
30pF
R27
2K
Q4
C2
15pF
R24
5K
Q7 Q12
Q8
R3
3.7K
Q5
R22
1.0K
Q6
Q26
R25
4.7K
C5
6pF
R19
12K
Q11A
R7
6.57K
R6
370
Q11B
R21
8K
R10
600
R11
60
R28
10
R12
0.3
Q19
6.2V
R8
300
Q15
Q16
Q18
6.2V
Q14B
Q17
Q25
R26
0.3
R15
60K
OUT
Q9
R4
2.4K
R5
12K
R23
60
Q10
ADJ
3
GM317L
V2.01
GM317L
3-TERMINAL 100mA
ADJUSTABLE REGULATOR
Electrical Characteristics
(Unless
otherwise noted, V
I
- V
O
= 5V and I
O
= 40mA.
T
J
= 0°C to
125°C, unless otherwise noted)
Parameter
Line Regulation (note 2)
Symbol
ΔV
OI
Test Condition
3V
≤
V
IN
– V
OUT
≤
40V, T
A
= 25°C
3V
≤
V
IN
– V
OUT
≤
40V,
10mA
≤
I
OUT
≤
100mA,
T
A
= 25°C
V
O
≤
5V
V
O
>
5V
V
O
≤
5V
V
O
>
5V
Min
Typ
0.01
0.02
5
0.1
20
0.3
50
Max
0.04
0.07
25
0.5
70
1.5
100
5.0
1.3
10
Unit
%/V
mV
%/ V
O
mV
%/ V
O
µA
µA
V
mA
mA
Load regulation
ΔV
OL
10mA
≤
I
OUT
≤
100mA
Adjustment Pin Current
Adjustment Pin Current
Change
Reference Voltage
I
ADJ
ΔI
ADJ
3V
≤
V
IN
– V
OUT
≤
40V
10mA
≤
I
OUT
≤
100mA
3V
≤
V
IN
– V
OUT
≤
40V,
10mA
≤
I
OUT
≤
100mA,
1.2
0.2
1.25
3.5
25
100
50
200
65
66
80
0.3
0.003
Minimum Load Current
Maximum Output Current
I
O(MAX)
V
IN
– V
OUT
≤
40V
V
IN
– V
OUT
≤
40V, T
A
= 25°C
V
IN
– V
OUT
≤
15V
V
OUT
= 10V, f = 120Hz
Ripple Rejection Ratio
V
OUT
= 10V, f = 120Hz, 10μF
capacitor between ADJ and GND
T
A
= 125
O
C, 1000hr
10Hz
≤
f
≤
10KHz, T
A
= 25°C
dB
%
%
Long Term Stability
(Note 3)
Output Noise Voltage
Note 1:
All characteristics are measured with a 0.1µF capacitor across the input and a 1µF capacitor across the output.
Note 2:
Input regulation is expressed here as the percentage change in output voltage per 1V change at the input.
Note 3:
Since long-term drift cannot be measured on the individual devices prior to shipment, this specification is not intended to
be a guarantee or warranty. It is an engineering estimate of the average drift to be expected from lot to lot.
GM317L
V2.01
4
GM317L
3-TERMINAL 100mA
ADJUSTABLE REGULATOR
Application Information
Basic Circuit Operation
The GM317L is a 3- terminal floating regulator. In operation, tit develops and maintains a nominal 1.25V
reference (V
REF
) between its output and adjustment terminal. This reference voltage is converted to a
programming current flow through R2 to ground.
The regulated output voltage is given by:
V
OUT
V
IN
GM317L
V
REF
Adjust
R1
I
PROG
I
ADJ
R2
R2
V
OUT
= V
REF
(1 + R1 ) + I
ADJ
R2
V
REF
= 1.25V typical
Basic Circuit Configuration
Since the current from the adjustment terminal (I
ADJ
) represents an error term in the equation, the GM317Lwas
designed to minimize I
ADJ
and make it very constant with line and load changes. To do this, all quiescent
operating current is returned to the output establishing a minimum load current requirement. If there is
insufficient load on the output, the output will rise.
Since the GM317L is a floating regulator, it is only the voltage differential across the circuit which is important to
performance, and operation at high voltages with respect to ground is possible.
Load Regulation
The GM317L is capable of providing extremely good load regulation, but a few precautions are needed to obtain
maximum performance. For best performance, the programming resistor R1 should be connected as close to
the regulator as possible to minimize line drops which effectively appear in series with the reference, thereby
degrading regulation. The ground end of R2 can be returned near the load ground to provide remote ground
sensing and improve load regulation.
External Capacitors
A 0.1µF disc or 1.0µF tantalum input bypass capacitor C
IN
is recommended to reduce the sensitivity to input line
impedance. The adjustment terminal may be bypassed to ground to improve ripple rejection. This capacitor C
ADJ
prevents ripple from being amplified as the output voltage is increased. A 10µF capacitor should improve ripple
rejection about 15 dB at 120Hz in a 10V application.
Although the GM317L is stable with no output capacitance, like any feedback circuit, certain values of external
capacitance can cause excessive ringing. An output capacitance C
O
in the form of a 1.0µF tantalum or 25µF
aluminum electrolytic capacitor on the output swamps this effect and insures stability.
Protection Diodes
When external capacitors are used with any IC regulator, it is sometimes necessary to add protection diodes to
prevent the capacitors from discharging through low current points into the regulator.
The figure below shows the GM317L with the recommended protection diodes for output for output voltage in
excess of 25V or high capacitance values (C
O
> 25µF, C
ADJ
> 10µF). Diode D1 prevents C
O
from discharging
thru the IC during an input short circuit. Diode D2 protects against capacitor C
ADJ
discharging through the IC
during an output short circuit. The combination of diodes D1 and D2 prevents C
ADJ
from discharging through the
IC during an input short circuit.
D1
1N4002
V
OUT
V
IN
GM317L
R1
C
IN
Adjust
R2
C
ADJ
C
O
D2
1N4002
5
GM317L
V2.01
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EEWORLD
