TS432I
Adjustable Precision Shunt Regulator
SOT-23
Pin Definition:
1. Reference
2. Cathode
3. Anode
General Description
The TS432AI/TS432BI is a three-terminal adjustable shunt regulator with specified thermal stability. The output voltage
may be set to any value between V
REF
(approximately 1.24V) and 18V with two external resistors. The
TS432AI/TS432BI has a typical output impedance of 0.05Ω. Active output circuitry provides a very sharp turn-on
characteristic, making the TS432AI/TS432BI excellent replacement for zener diode in many applications.
Features
●
Precision Reference Voltage
TS432AI – 1.24V±1%
TS432BI – 1.24V±0.5%
●
●
●
●
●
●
●
Minimum Cathode Current for Regulation: 20µA(typ.)
Equivalent Full Range Temp. Coefficient: 50ppm/ ºC
Programmable Output Voltage up to 18V
Fast Turn-On Response
Sink Current Capability of 80µA to 100mA
Low Dynamic Output Impedance: 0.2Ω
Low Output Noise
Ordering Information
Part No.
TS432xIX RF
TS432xIX RFG
TS432xIX RK
TS432xIX RKG
Package
SOT-23
SOT-23
SOT-23
SOT-23
Packing
3kpcs / 7” Reel
3kpcs / 7” Reel
10kpcs / 13” Reel
10kpcs / 13” Reel
Note:
“G” denote for Halogen Free Product
Note:
Where
xx
denotes voltage tolerance
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 Ratings
(T
A
= 25˚C unless otherwise noted)
Parameter
Cathode Voltage (Note 1)
Continuous Cathode Current Range
Reference Input Current Range
Power Dissipation
Junction Temperature
Operation Temperature Range
Storage Temperature Range
TO-92
SOT-23
Symbol
V
KA
I
K
I
REF
P
D
T
J
T
OPER
T
STG
Limit
18
100
3
0.625
0.35
+150
-40 ~ +105
-65 ~ +150
Unit
V
mA
mA
W
o
o
o
C
C
C
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
1/10
Version: C14
TS432I
Adjustable Precision Shunt Regulator
Recommend Operating Condition
Parameter
Cathode Voltage (Note 1)
Continuous Cathode Current Range
Symbol
V
KA
I
K
Limit
18
100
Unit
V
mA
Recommend Operating Condition
Parameter
TS432AI
TS432BI
Deviation of reference input
voltage
Radio of change in Vref to
change in cathode Voltage
Reference
voltage
Reference Input current
Deviation of reference input
current, over temp.
Off-state Cathode Current
Dynamic Output Impedance
Symbol
V
REF
∆V
REF
∆V
REF
/∆V
KA
I
REF
∆I
REF
I
KA(off)
|Z
KA
|
Test Conditions
V
KA
=V
REF
, I
K
=10mA (Figure 1)
o
Ta=25 C
V
KA
=V
REF,
I
K
=10mA
Ta= full range (Figure 1)
I
KA
=10mA, V
KA
= 18V to V
REF
(Figure 2)
R1=10KΩ, R2=
∞
, I
KA
=10mA
Ta= full range (Figure 2)
R1=10KΩ, R2=
∞
, I
KA
=10mA
Ta= full range (Figure 2)
V
REF
=0V (Figure 3),
V
KA
=18V
f<1KHz, V
KA
=V
REF
I
KA
=1mA to 100mA (Figure 1)
Min
1.227
1.233
--
--
--
--
--
--
Typ
1.240
10
-1.0
0.25
0.04
0.125
0.2
Max
1.252
1.246
25
-2.7
0.5
0.08
0.5
0.4
Unit
V
mV
mV/V
µA
µA
µA
Ω
Minimum operating cathode
I
KA(min)
V
KA
=V
REF
(Figure 1)
--
60
80
µA
current
* The deviation parameters
∆V
REF
and
∆I
REF
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,
αV
REF
is defined as:
Where:
T2-T1
= full temperature change.
αV
REF
can be positive or negative depending on whether V
REF
Min. or V
REF
Max occurs at the lower ambient
temperature. Example:
∆V
REF
=7.2mV and the slope is positive, V
REF
=1.241V at 25
o
C,
∆T=125
o
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:
2/10
Version: C14
TS432I
Adjustable Precision Shunt Regulator
Test Circuits
Figure 1: V
KA
= V
REF
Figure 2: V
KA
> V
REF
Figure 3: Off-State Current
Additional Information – Stability
When The TS432AI/432BI is used as a shunt regulator, there are two options for selection of C
L
, are recommended for optional
stability:
A)
B)
No load capacitance across the device, decouple at the load.
Large capacitance across the device, optional decoupling at the load.
The reason for this is that TS432AI/432BI exhibits instability with capacitances in the range of 10nF to 1µF (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 0.1µF 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 (10µF) 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 TS432AI/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
≥10µF.
Applications Examples
Figure 4: Voltage Monitor
Figure 5: Output Control for Three Terminal
Fixed Regulator
3/10
Version: C14
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
4/10
Version: C14
TS432I
Adjustable Precision Shunt Regulator
Applications Examples (Continue)
V
IN
<V
REF
>V
REF
V
OUT
V+
≈0.74V
Figure 12: Single-Supply
Comparator with Temperature-
Compensated Threshold
Figure 13: Constant Current
Sink
Figure 14: Delay Timer
5/10
Version: C14
DSP and ARM Processors
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