TS432I
Adjustable Precision Shunt Regulator
1/12 Version: A0B
TO-92
SOT-23
SOT-25
General Description
The TS432I/432AI/TS432BI is a three-terminal adjustable shunt regulator with specified thermal stability. The output
voltage may be set to any value between Vref (approximately 1.24V) and 18V with two external resistors. The
TS432I/432AI/TS432BI has a typical output impedance of 0.05. Active output circuitry provides a very sharp turn-on
characteristic, making the TS432I/432AI/TS432BI excellent replacement for zener diode in many applications.
Ordering Information
Part No. Package Packing
TS432xIT B0 TO-92 1Kpcs / Bulk
TS432xIT A3 TO-92 2Kpcs / Ammo
TS432xIX RF SOT-23 3Kpcs / 7” Reel
TS432xIX5 RF SOT-25 3Kpcs / 7” Reel
Note: Where xx denotes voltage tolerance
Blank: ±2%
A: ±1%
B: ±0.5%
Features
Precision Reference Voltage
TS432I – 1.24V±2%
TS432AI – 1.24V±1%
TS432BI – 1.24V±0.5%
Minimum Cathode Current for Regulation: 20uA(typ.)
Equivalent Full Range Temp. Coefficient: 50ppm/ ºC
Programmable Output Voltage up to 18V
Fast Turn-On Response
Sink Current Capability of 80uA to 100mA
Low Dynamic Output Impedance: 0.2
Low Output Noise
Application
Voltage Monitor
Delay Timmer
Constant –Current Source/Sink
High-Current Shunt Regulator
Crow Bar
Over-Voltage / Under-Voltage Protection
Block Diagram
Absolute Maximum Rating (Ta = 25 oC unless otherwise noted)
Parameter Symbol Limit Unit
Cathode Voltage (Note 1) Vka 18 V
Continuous Cathode Current Range Ik 100 mA
Reference Input Current Range Iref 3 mA
Power Dissipation TO-92
SOT-23
SOT-25
Pd
0.625
0.35
0.35
W
Junction Temperature TJ +150 oC
Operation Temperature Range TOPER -40 ~ +105 oC
Storage Temperature Range TSTG -65 ~ +150 oC
Note 1: Voltage values are with respect to the anode terminal unless otherwise noted.
Note 2: Rating apply to ambient temperature at 25oC
Pin Definition:
1. Reference
2. Cathode
3. Anode
Pin Definition:
1. Reference
2. Anode
3. Cathode
Pin Definition:
1. N/C
2. N/C *
3. Cathode
4. Reference
5. Anode
* (pin 2 is connect to substrate
and must be connected to Anode
or left o
p
en
)
TS432I
Adjustable Precision Shunt Regulator
2/12 Version: A0B
Recommend Operating Condition
Parameter Symbol Limit Unit
Cathode Voltage (Note 1) Vka 18 V
Continuous Cathode Current Range Ik 100 mA
Recommend Operating Condition
Parameter Symbo Test Conditions Min Typ Max Unit
TS432I 1.215 1.264
TS432AI 1.227 1.252
Reference voltage
TS432BI
Vref Vka =Vref, Ik=10mA (Figure 1)
Ta=25 oC 1.233
1.240
1.246
V
Deviation of reference input
voltage Vref Vka =Vref, Ik=10mA
Ta= full range (Figure 1) -- 10 25 mV
Radio of change in Vref to
change in cathode Voltage Vref/Vka Ika=10mA, Vka = 18V to Vref
(Figure 2) -- -1.0 -2.7 mV/V
Reference Input current Iref R1=10K, R2=
∞
, Ika=10mA
Ta= full range (Figure 2) -- 0.25 0.5 uA
Deviation of reference input
current, over temp. Iref R1=10K, R2=
∞
, Ika=10mA
Ta= full range (Figure 2) -- 0.04 0.08 uA
Off-state Cathode Current Ika(off) Vref=0V (Figure 3),
Vka=18V -- 0.125 0.5 uA
Dynamic Output Impedance |Zka| f<1KHz, Vka=Vref
Ika=1mA to 100mA (Figure 1) -- 0.2 0.4
Minimum operating cathode
current Ika(min) Vka=Vref (Figure 1) -- 60 80 uA
* The deviation parameters Vref and Iref are defined as difference between the maximum value and minimum value
obtained over the full operating ambient temperature range that applied.
* The average temperature coefficient of the
reference input voltage, αVref is defined as:
Where: T2-T1 = full temperature change.
αVref can be positive or negative depending on whether Vref Min. or Vref Max occurs at the lower ambient
temperature. Example: Vref=7.2mV and the slope is postive, Vref=1.241V at 25oC, T=125 oC
* The dynamic impedance ZKA is defined as:
* When the device operating with two external resistors, R1 and R2, (refer to Figure 2) the total dynamic impedance of
the circuit is given by:
TS432I
Adjustable Precision Shunt Regulator
3/12 Version: A0B
Test Circuits
Figure 1: Vka = Vref
Figure 2: Vka > Vref
Figure 3: Off-State Current
Additional Information – Stability
When The TS432I/432AI/432BI is used as a shunt regulator, there are two options for selection of CL, are recommended for optional
stability:
A) No load capacitance across the device, decouple at the load.
B) Large capacitance across the device, optional decoupling at the load.
The reason for this is that TS432I/432AI/432BI exhibits instability with capacitances in the range of 10nF to 1uF (approx.) at light
cathode current up to 3mA (typ). The device is less stable the lower the cathode voltage has been set for. Therefore while the
device will be perfectly stable operating at a cathode current of 10mA (approx.) with a 0.1uF capacitor across it, it will oscillate
transiently during start up as the cathode current passes through the instability region. Select a very low capacitance, or alternatively
a high capacitance (10uF) will avoid this issue altogether. Since the user will probably wish to have local decoupling at the load
anyway, the most cost effective method is to use no capacitance at all directly across the device. PCB trace/via resistance and
inductance prevent the local load decoupling from causing the oscillation during the transient start up phase.
Note: if the TS432I/432AI/432BI is located right at the load, so the load decoupling capacitor is directly across it, then this capacitor
will have to be 1nF or 10uF.
Applications Examples
Figure 4: Voltage Monitor
Figure 5: Output Control for Three Terminal
Fixed Regulator
TS432I
Adjustable Precision Shunt Regulator
4/12 Version: A0B
Applications Examples (Continue)
Figure 6: Shunt Regulator
Figure 7: High Current Shunt Regulator
Figure 8: Series Pass Regulator
Figure 9: Constant Current Source
Figure 10: TRIAC Crowbar
Figure 11: SCR Crowbar
TS432I
Adjustable Precision Shunt Regulator
5/12 Version: A0B
Applications Examples (Continue)
Vin Vout
<Vref V+
>Vref 0.74V
Figure 12: Single-Supply
Comparator with Temperature-
Compensated Threshold
Figure 13: Constant Current Sink
Figure 14: Delay Timer
TS432I
Adjustable Precision Shunt Regulator
6/12 Version: A0B
Typical Performance Characteristics
Test Circuit for Voltage Amplification
Figure 14: Small-Signal Voltage Gain and Phase Shift vs. Frequency
Test Circuit for Reference Impedance
Figure 15: Reference Impedance vs. Frequency
TS432I
Adjustable Precision Shunt Regulator
7/12 Version: A0B
Typical Performance Characteristics
The areas under the curves represent conditions that may
cause the device to oscillate. For curves B, C, and D, R2 and
V+ were adjusted to establish the initial VKA and IKA
conditions with CL=0. VBATT and CL then were adjusted to
determine the ranges of stability.
Test Circuit for Curve A
Test Circuit for Curve B, C and D
Figure 16: Stability Boundary Condition
Test Circuit for Pulse Response, Ik=1mA
Figure 17: Pulse Response
TS432I
Adjustable Precision Shunt Regulator
8/12 Version: A0B
Electrical Characteristics
Figure 18: Reference Voltage vs. Temperature
Figure 19: Reference Current vs. Temperature
Figure 20: Cathode Current vs. Cathode Voltage
TS432I
Adjustable Precision Shunt Regulator
9/12 Version: A0B
TO-92 Mechanical Drawing
Marking Diagram
X = Tolerance Code
(A = ±1%, B = ±0.5%, Blank = ±2%,)
Y = Year Code
M = Month Code
(A=Jan, B=Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep,
J=Oct, K=Nov, L=Dec)
L = Lot Code
TO-92 DIMENSION
MILLIMETERS INCHES
DIM MIN MAX MIN MAX
A 4.30 4.70 0.169 0.185
B 4.30 4.70 0.169 0.185
C 14.30(typ) 0.563(typ)
D 0.43 0.49 0.017 0.019
E 2.19 2.81 0.086 0.111
F 3.30 3.70 0.130 0.146
G 2.42 2.66 0.095 0.105
H 0.37 0.43 0.015 0.017
TS432I
Adjustable Precision Shunt Regulator
10/12 Version: A0B
SOT-23 Mechanical Drawing
Marking Diagram
X = Device Code
(D = TS432AI, E = TS432BI, F = TS432I,)
3 = SOT-23 package
Y = Year Code
M = Month Code
(A=Jan, B=Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep,
J=Oct, K=Nov, L=Dec)
L = Lot Code
SOT-23 DIMENSION
MILLIMETERS INCHES
DIM MIN MAX MIN MAX.
A 0.95 BSC 0.037 BSC
A1 1.9 BSC 0.074 BSC
B 2.60 3.00
0.102 0.118
C 1.40 1.70
0.055 0.067
D 2.80 3.10
0.110 0.122
E 1.00 1.30
0.039 0.051
F 0.00 0.10
0.000 0.004
G 0.35 0.50
0.014 0.020
H 0.10 0.20
0.004 0.008
I 0.30 0.60
0.012 0.024
J 5º 10º 5º 10º
TS432I
Adjustable Precision Shunt Regulator
11/12 Version: A0B
SOT-25 Mechanical Drawing
Marking Diagram
X = Device Code
(D = TS432AI, E = TS432BI, F = TS432I,)
5 = SOT-25 package
Y = Year Code
M = Month Code
(A=Jan, B=Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep,
J=Oct, K=Nov, L=Dec)
L = Lot Code
SOT-25 DIMENSION
MILLIMETERS INCHES
DIM MIN MAX MIN MAX.
A+A1 0.09 1.25 0.0354 0.0492
B 0.30 0.50 0.0118 0.0197
C 0.09 0.25 0.0035 0.0098
D 2.70 3.10 0.1063 0.1220
E 1.40 1.80 0.0551 0.0709
E 1.90 BSC 0.0748 BSC
H 2.40 3.00 0.09449 0.1181
L 0.35 BSC 0.0138 BSC
1 0º 10º 0º 10º
S1 0.95 BSC 0.0374 BSC
TS432I
Adjustable Precision Shunt Regulator
12/12 Version: A0B
Notice
Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf,
assumes no responsibility or liability for any errors or inaccuracies.
Information contained herein is intended to provide a product description only. No license, express or implied, to any
intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of sale for
such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale
and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability,
or infringement of any patent, copyright, or other intellectual property right.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers
using or selling these products for use in9 such applications do so at their own risk and agree to fully indemnify TSC for
any damages resulting from such improper use or sale.
