AHK432
Adjustable Low Voltage Shunt Regulator
General Description
The AHK432 is a low voltage adjustable shunt refer-
ence with thermal stability guaranteed over the full
industrial temperature range. This 3-terminal regula-
tor has an output voltage range that extends from
V
REF
(1.24V) to 20V, giving designers outstanding
flexibility in the development of power supplies and
instrumentation. With a low operating current of
60µA, the AHK432 is well suited for battery-powered
portable electronic applications. It also has a sharp
turn-on characteristic and a dynamic resistance of
only 50mW making it an excellent replacement for
zener diodes in low tempco designs.
The AHK432 is available in the surface-mount 3 or
5 pin SOT-23, as well as the through hole TO-92.
Three voltage tolerance options are offered in each
package: ±0.5%, ±1%, and ±2%.
Features
•
•
•
•
•
•
PowerManager
™
SmartSwitch
™
Wide output voltage range (1.24 to 20V)
Operating current from 60µA to 100mA
Low dynamic output resistance of 50mΩ
±0.5% trimmed voltage reference
10mV typ. V
REF
deviation, from -40 to +105°C
Surface mount 3 or 5 pin SOT-23 or through-
hole 3 pin TO-92 packages
Preliminary Information
Applications
•
•
•
•
•
•
•
Notebook computers
Isolated feedback in switching power supplies
Adjustable and programmable supplies
Linear regulators (External Reference)
Instrumentation
Medical Electronics*
Global voltage reference for multiple power
supplies
Typical Application
IN
R
L
OUT
R1
Adjustable regulator:
AHK432
R2
OUT = V
REF
R1 + R2
R2
432.2001.11.0.96
1
AHK432
Adjustable Low Voltage Shunt Regulator
Absolute Maximum Ratings
Symbol
V
Z
I
Z
I
REF
T
J
Θ
JA
P
D
T
LEAD
(T
A
=25°C unless otherwise noted)
Value
20
100
3
-40 to 150
160
410
780
300
260
Description
Cathode Voltage
Continuous Cathode Current
Reference Current
Operating Junction Temperature Range
Maximum Thermal Resistance
Maximum Power Dissipation
Maximum Soldering Temperature (at Leads)
TO-92
SOT-23-3, SOT-23-5
TO-92
SOT-23-3, SOT-23-5
Units
V
mA
mA
°C
°C/W
mW
°C
Note: Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at con-
ditions other than the operating conditions specified is not implied. Only one Absolute Maximum rating should be applied at any one time.
Electrical Characteristics
Symbol
Description
Reference
Voltage
V
REF
Temp
Deviation
Ratio of
Change in V
REF
to Change in
Cathode Voltage
I
REF
Reference
Input Current
I
REF(DEV)
I
REF
Temp
Deviation
R1=10kΩ,
(T
J
=25°C unless otherwise noted)
AHK432 0.5%
AHK432 1.0%
typ
AHK432 2.0%
max Units
Conditions
V
Z
=V
REF
I
Z
=10mA
(test circuit 1)
T
A
=-40 to +105°C,
V
Z
=V
REF
, I
Z
=10mA
(test circuit 1)
I
Z
=10mA,
∆V
Z
=16V to V
REF
(test circuit 2)
min
typ
max min
Max min typ
T
A
=25°C 1.234 1.240 1.246 1.228 1.240 1.252 1.215 1.240 1.265
T
A
=-40
1.222
to +105°C
10
V
1.258 1.215
25
10
1.265 1.200
25
10
1.280
25
mV
V
REF
V
DEV
∆V
REF
/∆V
Z
-1.0
-2.7
-1.0
-2.7
-1.0
-2.7
mV/V
0.15
0.5
0.15
0.5
0.15
0.5
µA
R2=∞ , I
Z
=10mA
(test circuit 2)
T
A
=-40 to +105°C
R1=10kΩ , R2=∞ ,
I
Z
=10mA
(test circuit 2)
V
REF
=0V
(test circuit 3)
f<1kHz, V
Z
=V
REF
,
I
Z
=100mA to 100mA
(test circuit 1)
V
Z
=V
REF
(test circuit 1)
V
Z
=6V
V
Z
=16V
0.04
0.04
0.05
0.1
0.5
0.2
0.04
0.04
0.05
0.1
0.5
0.2
0.04
0.04
0.05
0.1
0.5
0.2
Ω
µA
0.1
0.4
0.1
0.4
0.1
0.4
µA
I
Z(OFF)
R
Z
Off State
Cathode Current
Dynamic
Output
Impedance
Minimum
Operating
Current
I
Z(MIN)
60
80
60
80
60
80
µA
2
432.2001.11.0.96
AHK432
Adjustable Low Voltage Shunt Regulator
Typical Characteristics
(Unless otherwise noted, T
A
= 25°C, I
Z
= 10mA)
Cathode Current vs. Cathode Voltage
15
Cathode Current vs. Cathode Voltage
200
Cathode Current (µA)
-1
-0.5
0
0.5
1
1.5
Cathode Current (mA)
10
5
0
-5
-10
-15
150
100
50
0
-50
-100
-150
-200
-1
-0.5
0
0.5
1
1.5
Cathode Voltage ( V)
Cathode Voltage (V)
Reference Voltage vs. Temperature
1.252
180
Reference Current vs. Temperature
Reference Voltage (V )
1.248
1.244
1.24
1.236
1.232
-50
-25
0
25
50
75
100
125
Reference Curre nt (nA)
I
Z
=10mA
160
140
120
100
80
60
40
20
0
-50
-25
0
25
50
75
I
Z
=10mA
R
1
=10kΩ
R
2
=Open
100
125
Junction Temperature (°C)
Junction Temperatur e (°C)
Cathode Current vs. Temperature
80
Ratio of
∆V
REF
/
∆V
Z
vs. Temperature
0
Cathode Current (nA)
70
60
50
40
30
20
10
0
-50
Ratio (µV/V)
V
Z
=5V
V
REF
=0V
(Off-state)
-100
-200
-300
-400
-500
-600
I
Z
=10mA
dV
Z
=V
REF
to 16V
-25
0
25
50
75
100
125
-50
-25
0
25
50
75
100
125
Junction Temperature (°C)
Junction Temperature (°C)
4
432.2001.11.0.96
AHK432
Adjustable Low Voltage Shunt Regulator
(Unless otherwise noted, T
A
= 25°C, I
Z
= 10mA)
Cathode Impedance vs. Temperature
16%
10
Impedance vs. Frequency
Normalized Impedance
12%
8%
4%
0%
-4 %
-50
Impedance (Ω)
1
0.1
-25
0
25
50
75
100
125
0.01
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
Junction Temperature (°C)
Frequency ( Hz )
Gain and Phase vs. Frequency
120
100
180
150
120
90
60
30
0
-30
1.E+06
V
OUT
V
IN
13.7k
AHK432
8.25k
5V
169
Ω
Gain (dB)
80
60
40
20
0
-20
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
Frequency (Hz)
Test Circuit for Voltage
Gain and Phase
Stability Boundary
1k
100
80
I
Z
Stable
Stable
Current (mA)
R1=10k
C
L
60
40
Unstable
20
AHK432
R2
V
REF
=V
Z
0
10.E+0
100.E+0
1.E+3
10.E+3
100.E+3
1.E+6
10.E+6
Load Capacitance (pF)
Test Circuit for Stability
432.2001.11.0.96
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