TS432I
Adjustable Precision Shunt Regulator
TO-92
Pin Definition:
1. Reference
2. Anode
3. Cathode
SOT-23
Pin Definition:
1. Reference
2. Cathode
3. Anode
SOT-25
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 open)
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 0.05Ω. Active output circuitry provides a very sharp turn-on
characteristic, making the TS432I/432AI/TS432BI excellent replacement for zener diode in many applications.
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: 0.2Ω
Low Output Noise
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%
●
●
●
●
●
●
●
Block Diagram
Application
●
●
●
●
●
●
Voltage Monitor
Delay Timmer
Constant –Current Source/Sink
High-Current Shunt Regulator
Crow Bar
Over-Voltage / Under-Voltage Protection
Absolute Maximum Rating
(Ta = 25 oC unless otherwise noted)
Parameter
Cathode Voltage (Note 1)
Continuous Cathode Current Range
Reference Input Current Range
Power Dissipation
Symbol
Vka
Ik
Iref
Limit
Unit
V
mA
mA
W
o
o
18
100
3
TO-92
0.625
SOT-23
Pd
0.35
SOT-25
0.35
Junction Temperature
T
J
+150
Operation Temperature Range
T
OPER
-40 ~ +85
Storage Temperature Range
T
STG
-65 ~ +150
Note 1: Voltage values are with respect to the anode terminal unless otherwise noted.
o
Note 2: Rating apply to ambient temperature at 25 C
C
C
o
C
1/12
Version: A07
TS432I
Adjustable Precision Shunt Regulator
Recommend Operating Condition
Parameter
Cathode Voltage (Note 1)
Continuous Cathode Current Range
Symbol
Vka
Ik
Limit
18
100
Unit
V
mA
Recommend Operating Condition
Parameter
TS432I
Reference voltage
TS432AI
TS432BI
Vref
Symbo
Test Conditions
Vka =Vref, Ik=10mA (Figure 1)
o
Ta=25 C
Vka =Vref, Ik=10mA
Ta= full range (Figure 1)
Ika=10mA, Vka = 18V to Vref
(Figure 2)
R1=10KΩ, R2=
!
, Ika=10mA
Ta= full range (Figure 2)
R1=10KΩ, R2=
!
, Ika=10mA
Ta= full range (Figure 2)
Vref=0V (Figure 3),
Vka=18V
f<1KHz, Vka=Vref
Ika=1mA to 100mA (Figure 1)
Min
1.215
1.227
1.233
--
--
--
--
--
--
Typ
1.240
Max
1.264
1.252
1.246
25
-2.7
0.5
0.08
0.5
0.4
Unit
V
Deviation of reference input
voltage
Radio of change in Vref to
change in cathode Voltage
Reference Input current
Deviation of reference input
current, over temp.
Off-state Cathode Current
Dynamic Output Impedance
∆Vref
∆Vref/∆Vka
Iref
∆Iref
Ika(off)
|Zka|
10
-1.0
0.25
0.04
0.125
0.2
mV
mV/V
uA
uA
uA
Ω
Minimum operating cathode
Ika(min)
Vka=Vref (Figure 1)
--
60
80
uA
current
* 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
o
o
temperature. Example:
∆Vref=7.2mV
and the slope is postive, Vref=1.241V at 25 C,
ΔT=125
C
* The dynamic impedance Z
KA
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:
2/12
Version: A07
TS432I
Adjustable Precision Shunt Regulator
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 C
L
, 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
3/12
Version: A07
TS432I
Adjustable Precision Shunt Regulator
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
4/12
Version: A07
TS432I
Adjustable Precision Shunt Regulator
Applications Examples (Continue)
Vin
<Vref
>Vref
Vout
V+
≈0.74V
Figure 12: Single-Supply
Comparator with Temperature-
Compensated Threshold
Figure 13: Constant Current Sink
Figure 14: Delay Timer
5/12
Version: A07