HT317L
100 mA Adjustable Output, Positive Voltage Regulator
The HT317L is an adjustable 3−terminal positive voltage regulator capable of supplying in excess of 100 mA 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 them essentially blow−out proof. The HT317L serves a wide variety of applications including
local, on card regulation. This device can also be used to make a programmable output regulator, or by
connecting a fixed resistor between the adjustment and output, the HT317L can be used as a precision current
regulator.
Features
Output Current in Excess of 100 mA
Output Adjustable Between 1.2 V and 37 V
Internal Thermal Overload Protection
Internal Short Circuit Current Limiting
Output Transistor Safe−Area Compensation
Floating Operation for High Voltage Applications
Standard 3−Lead Transistor Package
Eliminates Stocking Many Fixed Voltages
NCV Prefix for Automotive and Other Applications Requiring
Unique Site and Control Change Requirements; AEC−Q100
Qualified and PPAP Capable
These are Pb−Free Devices
PIN CONNECTIONS
8
1
SOP8
R SUFFIX
HT317LRZ
BENT LEAD
TAPE & REEL
AMMO PACK
1
Simplified Application
Vin
Pin 1. V in
2. V out
3. Vout
4. Adjust
5. N.C.
6. Vout
7. Vout
8. N.C.
2 3
TO92
P
SUFFIX
HT317LRPZ
Pin 1. Adjust
2. Vout
3. Vin
Vout
HT317L
Vin
R1
240
IAdj
Cin*
0.1µF
+ C **
O
1.0µF
Adjust
Vout
1
XDFN4
Q SUFFIX
HT317LRQZ
Pin A1. Adjust
A2. Vout
B1. Vin
B2. N.C.
R2
A1
A2
B1
B2
ADJ
(Top
Nc.
View)
TAB
* Cin is required if regulator is located an appreciable
distance from power supply filter.
** CO is not needed for stability, however,
it does improve transient response.
(
)
R
Vout = 1.25 V 1 + 2 + IAdj
R1
R2
1
SOT−89
H SUFFIX
HT317LRHZ
Pin 1. Adjust
2. Vout
3. Vin
Since I Adj is controlled to less than 100 µA, the error
associated with this term is negligible in most applications.
Rev. 01
HT317L
MAXIMUM RATINGS
Symbol
Value
Unit
Input−Output Voltage Differential
Rating
VI −VO
40
Vdc
Power Dissipation
Case 29 (TO−92)
TA = 25C
Thermal Resistance, Junction−to−Ambient
Thermal Resistance, Junction−to−Case
PD
R8JA
R8JC
Internally Limited
160
83
W
C/W
C/W
Case 751 (SOIC−8) (Note 1)
TA = 25C
Thermal Resistance, Junction−to−Ambient
Thermal Resistance, Junction−to−Case
PD
R8JA
R8JC
Internally Limited
180
45
W
C/W
C/W
TJ
−40 to +150
C
Tstg
−65 to +150
C
Operating Junction Temperature Range
Storage Temperature Range
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. SOIC−8 Junction−to−Ambient Thermal Resistance is for minimum recommended pad size. Refer to Figure 24 for Thermal Resistance
variation versus pad size.
2. This device series contains ESD protection and exceeds the following tests:
Human Body Model, 2000 V per MIL STD 883, Method 3015.
Machine Model Method, 200 V.
Vin
300
300
300
3.0k
6.8V
70
300
6.8V
350
18k
8.67k
500
130
400
5.1k
200k
6.3V
180 180
2.0k
6.0k
60
10
p 10
F p
F
2.5
Vout
2.4k
12.8k
50
Adjust
Figure 1. Representative Schematic Diagram
Rev. 01
HT317L
VCC
VOH - V OL
x 100
VOL
Line Regulation (%/V) =
*
VOH
VIH
Vout
V IL V in
VOL
HT317L
Adjust
Cin
0.1µF
R1 240
1%
RL
+
CO
IAdj
1µF
R2
1
%
* Pulse Testing Required:
1% Duty Cycle is suggested.
Figure 2. Line Regulation and 庄IAdj/Line Test Circuit
Load Regulation (mV) = V O (min Load) -VO (max Load)
VO (min Load) - VO (max Load)
Load Regulation (% VO) =
VO (min Load)
Vin *
X
100
V (min Load)
O
VO (max Load)
Vout
Vin
HT317L
IL
RL
(max Load)
240
R1 1%
Adjust
*
+
Cin
0.1µF
CO
IAdj
RL
(min Load)
1.0µF
R2
1%
* Pulse Testing Required:
1% Duty Cycle is suggested.
Figure 3. Load Regulation and 庄IAdj/Load Test Circuit
Vin
Vout
HT317L
IL
Adjust
R1
IAdj
VI
Cin
240
1%
Vref
RL
+
0.1µF
VO
CO
ISET
Pulse Testing Required:
1% Duty Cycle is suggested.
R2
1%
To Calculate R 2:
Vout = ISET R2 + 1.250 V
Assume I SET = 5.25 mA
1µ
F
Figure 4. Standard Test Circuit
Rev. 01
HT317L
14.30V
Vout
Vin
4.30V
f = 120 Hz
Vout = 1.25 V
HT317L
Adjust
Cin
D1 *
1N4002
240
1%
R1
0.1µF
CO
R2
RL
+
1µF
VO
+
1.65K
1%
10µF
**
* D1 Discharges C Adj if Output is Shorted to Ground.
**C Adj provides an AC ground to the adjust pin.
0.4
Vin = 45 V
Vout = 5.0 V
IL = 5.0 mA to 40 mA
0.2
RR, RIPPLE REJECTION (dB)
V out, OUTPUT VOLTAGE CHANGE (%)
Figure 5. Ripple Rejection Test Circuit
0
-0.2
Vin = 10 V
Vout = 5.0 V
IL = 5.0 mA to 100 mA
-0.4
-0.6
-0.8
80
70
IL = 40 mA
f = 120 Hz
Vout = 10 V
Vin = 14 V to 24 V
60
50
-1.0
-50
-25
0
25 50 75 100 125
TJ, JUNCTION TEMPERATURE (C)
150
-50
-25
Figure 6. Load Regulation
150
Figure 7. Ripple Rejection
0.50
V in -Vout , INPUT-OUTPUT VOLTAGE
DIFFERENTIAL (V)
2.5
TJ = 25C
IO, OUTPUT CURRENT (A)
0
25 50 75 100 125
TJ, JUNCTION TEMPERATURE (C)
0.40
0.30
0.20
TJ = 150C
0.10
0
2.0
IL = 100 mA
1.5
IL = 5 .0 mA
1.0
0.5
0
10
20
30
40
Vin-Vout, INPUT-OUTPUT VOLTAGE DIFFERENTIAL (V)
Figure 8. Current Limit
50
-50
-25
0
25 50 75 100 125
TJ, JUNCTION TEMPERATURE (C)
150
Figure 9. Dropout Voltage
Rev. 01
HT317L
100
4.5
90
TJ = 55C
TJ = 25C
TJ = 150C
4.0
3.5
RR, RIPPLE REJECTION (dB)
IB , QUIESCENT CURRENT (mA)
5.0
3.0
2.5
2.0
1.5
1.0
0.5
70
60
50
40
30
20
10
0
10
20
30
40
Vin-Vout, INPUT-OUTPUT VOLTAGE DIFFERENTIAL (V)
10
Figure 10. Minimum Operating Current
100
10 k
100 k 1.0 M
f, FREQUENCY (Hz)
1.250
1.240
Vin = 4.2 V
Vout = V ref
IL = 5.0 mA
1.230
IAdj, ADJUSTMENT PIN CURRENT (A)
80
1.220
70
65
Vin = 6.25 V
Vout = Vref
IL = 10 mA
IL = 100 mA
60
55
50
45
40
35
-50
-25
0
25
50
75 100 125 150
TJ, JUNCTION TEMPERATURE (C)
-50
0.4
Vin = 4.25 V to 41.25 V
Vout = Vref
IL = 5 mA
0.2
0
-0.2
-0.4
-0.6
-25
0
25
50
75 100 125 150
TJ, JUNCTION TEMPERATURE (C)
Figure 13. Adjustment Pin Current
NOISE VOLTAGE (V)
Figure 12. Temperature Stability
Vout , OUTPUT VOLTAGE CHANGE (%)
1.0 k
Figure 11. Ripple Rejection versus Frequency
1.260
V ref , REFERENCE VOLTAGE (V)
IL = 40 mA
Vin = 5.0 V 1.0 V PP
Vout = 1.25 V
80
Bandwidth 100 Hz to 10 kHz
10
8.0
6.0
-0.8
-1.0
4.0
-50
-25
0
25
50
75 100 125 150
TJ, JUNCTION TEMPERATURE (C)
Figure 14. Line Regulation
-50
-25
0
25
50
75 100 125 150
TJ, JUNCTION TEMPERATURE (C)
Figure 15. Output Noise
Rev. 01
Vout , OUTPUT VOLTAGE
DEVIATION (V)
1.5
1.0
CL = 1.0 µF;
C Adj = 10 µF
0.5
0
V in , INPUT
VOTLAGE CHANGE (V)
-0.5
Vout = 10 V
IL = 50 mA
TJ = 25C
-1.0
-1.5
CL = 0;
Without C Adj
1.0
Vin
0.5
0
0
10
20
30
40
0.3
0.2
CL = 1 µF; CAdj = 10 µF
0.1
0
-0.1
Vin = 15 V
Vout = 10 V
I NL = 50 mA
TJ = 25C
CL = 0.3 µF; CAdj = 10 µF
-0.2
I L , LOAD
CURRENT (mA)
Vout , OUTPUT
VOLTAGE DEVIATION (V)
HT317L
-0.3
100
IL
50
0
0
10
20
30
40
t, TIME (µs)
t, TIME (µs)
Figure 16. Line Transient Response
Figure 17. Load Transient Response
APPLICATIONS INFORMATION
Basic Circuit Operation
Load Regulation
The HT317L is a 3−terminal floating regulator. In
operation, the HT317L develops and maintains a nominal
1.25 V reference (Vref) between its output and adjustment
terminals. This reference voltage is converted to a
programming current (IPROG) by R1 (see Figure 13), and this
constant current flows through R2 to ground. The regulated
output voltage is given by:
The HT317L 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.
Vout = Vref (1 +
R2
) + IAdj R2
R1
Since the current from the adjustment terminal (IAdj)
represents an error term in the equation, the HT317L was
designed to control IAdj to less than 100 µA and keep it
constant. To do this, all quiescent operating current is
returned to the output terminal. This imposes the
requirement for a minimum load current. If the load current
is less than this minimum, the output voltage will rise.
Since the HT317L 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.
Vout
Vin
HT317L
+
R1
External Capacitors
A 0.1 µF disc or 1.0 µF tantalum input bypass capacitor
(Cin) is recommended to reduce the sensitivity to input line
impedance.
The adjustment terminal may be bypassed to ground to
improve ripple rejection. This capacitor (CAdj) prevents
ripple from being amplified as the output voltage is
increased. A 10 µF capacitor should improve ripple
rejection about 15 dB at 120 Hz in a 10 V application.
Although the HT317L is stable with no output
capacitance, like any feedback circuit, certain values of
external capacitance can cause excessive ringing. An output
capacitance (CO) in the form of a 1.0 µF tantalum or 25 µF
aluminum electrolytic capacitor on the output swamps this
effect and insures stability.
Vref
Adjust
IPROG
Vout
IAdj
R2
Vref = 1.25 V Typical
Figure 18. Basic Circuit Configuration
Rev. 01
HT317L
Protection Diodes
D1
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.
Figure 14 shows the HT317L with the recommended
protection diodes for output voltages in excess of 25 V or
high capacitance values (CO > 10 µF, CAdj > 5.0 µF). Diode
D1 prevents CO from discharging thru the IC during an input
short circuit. Diode D2 protects against capacitor CAdj
discharging through the IC during an output short circuit.
The combination of diodes D1 and D2 prevents CAdj from
discharging through the IC during an input short circuit.
1N4002
Vin
Vout
HT317L
+
Cin
R1
CO
D2
Adjust
1N4002
CAdj
R2
Figure 19. Voltage Regulator with
Protection Diodes
+25V
Vout
HT317L
VO
R1
IO
1.25k
Vin
Adjust
D1
D1
1N914
R2
500
* To provide current limiting of I O
to the system ground, the source of
the current limiting diode must be tied to
a negative voltage below - 7.25 V.
1N4002
Vin
Vout
HT317L
D2
1N914
+
1.0µF
120
Adjust
MPS2222
1N5314
Vref
R2 I
DSS
R1 =
TTL
Control
720
1.0k
VSS*
Vref
IOmax + IDSS
Minimum Vout = 1.25 V
VO < P OV + 1.25 V + VSS
ILmin - IP < IO < 100 mA - IP
As shown O < I O < 95 mA
D1 protects the device during an input short circuit.
Figure 20. Adjustable Current Limiter
Figure 21. 5.0 V Electronic Shutdown Regulator
Vin
R1
HT317L
Iout
Vout
I Adj
Adjust
Vout
Vin
R2
HT317L
240
Ioutmax =
50k
Adjust
R2
1N4002
MPS2907
+
I
10µF
outmax
=
Vref
R1
+ IAdj 三 1.25 V
R1
Vref
R1 + R2
+I
Adj
三 1.25 V
R1 + R 2
5.0 mA < I out < 100 mA
Figure 22. Slow Turn−On Regulator
Figure 23. Current Regulator
Rev. 01
HT317L
3.2
150
2.8
P D(max) for TA = 50C
2.4
130
110
2.0
Graph represents symmetrical layout
90
L
1.6
2.0 oz.
Copper
1.2
70
L
3.0 mm
50
0.8
RJA
30
0
10
0.4
20
30
40
PD, MAXIMUM POWER DISSIPATION (W)
R JA, THERMAL RESISTANCE
JUNCTION-TO-AIR (C/W)
170
50
L, LENGTH OF COPPER (mm)
Figure 24. SOP−8 Thermal Resistance and Maximum
Power Dissipation versus P.C.B. Copper Length
Rev. 01
HT317L
PACKAGE DIMENSIONS
TO−92 (TO−226)
Z SUFFIX
CASE 29−11
ISSUE AM
A
B
STRAIGHT LEAD
BULK PACK
R
P
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. CONTOUR OF PACKAGE BEYOND DIMENSION R
IS UNCONTROLLED.
4. LEAD DIMENSION IS UNCONTROLLED IN P AND
BEYOND DIMENSION K MINIMUM.
L
SEATING
PLANE
K
D
X X
G
J
H
V
C
SECTION X−X
1
N
DIM
A
B
C
D
G
H
J
K
L
N
P
R
V
INCHES
MIN
MAX
0.175
0.205
0.170
0.210
0.125
0.165
0.016
0.021
0.045
0.055
0.095
0.105
0.015
0.020
0.500
--0.250
--0.080
0.105
--0.100
0.115
--0.135
---
MILLIMETERS
MIN
MAX
4.45
5.20
4.32
5.33
3.18
4.19
0.407
0.533
1.15
1.39
2.42
2.66
0.39
0.50
12.70
--6.35
--2.04
2.66
--2.54
2.93
--3.43
---
N
A
R
BENT LEAD
TAPE & REEL
AMMO PACK
B
P
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ASME Y14.5M, 1994.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. CONTOUR OF PACKAGE BEYOND
DIMENSION R IS UNCONTROLLED.
4. LEAD DIMENSION IS UNCONTROLLED IN P
AND BEYOND DIMENSION K MINIMUM.
T
SEATING
PLANE
K
G
D
X X
J
V
1
C
SECTION X−X
DIM
A
B
C
D
G
J
K
N
P
R
V
MILLIMETERS
MIN
MAX
4.45
5.20
4.32
5.33
3.18
4.19
0.40
0.54
2.40
2.80
0.39
0.50
12.70
--2.04
2.66
1.50
4.00
2.93
--3.43
---
N
Rev. 01
HT317L
PACKAGE DIMENSIONS
SOIC−8 NB
D SUFFIX
CASE 751−07
ISSUE AK
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION 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 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
6. 751−01 THRU 751−06 ARE OBSOLETE. NEW
STANDARD IS 751−07.
−X−
A
8
5
S
B
0.25 (0.010) M
Y
M
1
4
K
−Y−
G
C
N X 45
DIM
A
B
C
D
G
H
J
K
M
N
S
。
SEATING
PLANE
−Z−
0.10 (0.004)
H
M
D
0.25 (0.010)
M
Z Y
S
X
J
S
MILLIMETERS
。
MIN
MAX
4.80
5.00
3.80
4.00
1.35
1.75
0.33
0.51
1.27 BSC
0.10
0.25
0.19
0.25
0.40
1.27
0
8
0.25
0.50
5.80
6.20
。
INCHES
。
MIN
MAX
0.189
0.197
0.150
0.157
0.053
0.069
0.013
0.020
0.050 BSC
0.004
0.010
0.007
0.010
0.016
0.050
0
8
0.010
0.020
0.228
0.244
。
SOLDERING FOOTPRINT*
1.52
0.060
7.0
0.275
0.6
0.024
4.0
0.155
1.270
0.050
SCALE 6:1
)
mm
(inches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
Rev. 01