ADJUSTABLE PRECISION SHUNT REGULATOR
FSP431
ELECTRICAL CHARACTERISTICS
(T
A
=25°C, Unless otherwise noted)
PARAMETER
SYMBOL
Reference Voltage
V
REF
Deviation of reference voltage
over full temperature range
V
I(dev)
(see Figure 1)
Ratio of change in reference
voltage to the change in cathode
∆V
REF
/∆V
KA
voltage
Reference Current
I
REF
Deviation of reference current
I
I(dev)
over full temperature range
(see Figure 1)
Minimum Cathode Current for
I
MIN
regulation
Off-state Cathode Current
I
OFF
Dynamic Impedance
∣Z
KA
∣
(see Figure 1)
TEST CONDITIONS
V
KA
= V
REF
, I
KA
=10mA
V
KA
= V
REF
, I
KA
=10mA
T
A
= full range
I
KA
=10mA
∆V
KA
=10V- V
REF
∆V
KA
=36V- 10V
MIN
2.47
TYP
2.495
4
-4.7
-1
2
0.8
0.4
0.1
0.2
MAX
2.52
25
-2.7
-2
4
1.2
0.6
0.5
0.5
UNIT
V
mV
mV/V
µA
µA
mA
mA
Ω
I
KA
=10mA, R1=10kΩ, R2=∞
I
KA
=10mA, R1=10kΩ, R2=∞
T
A
= full range
V
KA
= V
REF
V
KA
=36V, V
REF
=0
I
KA
=1mA to 100Ma, V
KA
= V
REF
f≤1kHz
The deviation parameters V
ref(dev)
and I
ref(dev)
are defined as the differences between the maximum and minimum
values obtained over the recommended temperature range. The average full-range temperature coefficient of the
reference voltage, V
ref,
is defined as:
Where :
∆TA
is the recommended operating free-air temperature range of the device.
αVref
can be positive or negative, depending on whether minimum Vref or maximum Vref, respectively , occurs at
the lower temperature.
Example : maximum Vref=2.496V at 30°C, minimum Vref =2.492V at 0°C, Vref=2.495V at 25°C,
Because minimum Vref occurs at the lower temperature, the coefficient is positive.
Calculating Dynamic Impedance
The dynamic impedance is defined as:
When the device is operating with two external resistors, the total dynamic impedance of the circuit is given by:
Figure 1: Calculating Deviation Parameters and Dynamic Impedance
3/15
2007-1-24
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