3
Date: 3/14/06 SPX2945 400mA Low Dropout Voltage Regulator with Shutdown ©Copyright 2006 Sipex Corporation
PARAMETER CONDITIONS MIN TYP MAX ♦ UNITS
(Note 2)
Feedback Pin Bieas Current 0.1 nA/°C
Temperature Coefficient
Output Leakage Current V
0H
=20V 0.01 1 µA
2 ♦
Output Low Voltage V
IN
=4.5V 150 250 mV
I
0L
=400µA 400 ♦
Upper Threshold Voltage (Note 6) 40 60 mV
25
Lower Threshold Voltage (Note 6) 75 95 mV
140 ♦
Hysteresis (Note 6) 15 mV
Input Logic Voltage Low (Regulator ON) 0.7 ♦ V
High (Regulator OFF) 1.3 2.0 ♦
Shutdown Pin Input Current VS=2.4V 30 50 µA
100 ♦
VS=26V 450 600
750 ♦
Regulator Output Current (Note 7) 10 3 µA
in Shutdown 20 ♦
Thermal Resistance TO-220-3 29.4 ♦
Theta Junction-Ambient θJA TO-263-3 31.4 ♦ °C/W
TO-263-5 31.2 ♦
NSOIC-8 128.4 ♦
SOT-223 62.3 ♦
TO-252 50 ♦
ELECTRICAL CHARACTERISTICS: Continued
Electrical characteristics at V
IN
= V
O
+1V, I
O
= 1mA, C
OUT
= 2.2µF, T
A
= 25°C, unless otherwise specified. ♦ applies over the
full operating temperature range.
Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by
the total temperature range.
Note 2: Unless otherwise specified all limits are guaranteed for T
j
= 25°C, V
IN
= 6V, I
L
= 1mA and C
L
= 2.2µF. Additional
conditions for the 8-pin versions are feedback tied to 5V/3.3V tap and output tied to output sense (V
OUT
= 5V) and
V
SHUTDOWN
≤ 0.8V.
Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes
in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 4: Line regulation for the SPX2945 is tested at 150°C for I
L
= 1 mA. For T
J
= 125°C, line regulation is guaranteed
by design.
Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below
its nominal value measured at 1V differential at very low values of programmed output voltage, the minimum input
supply voltage of 2V ( 2.3V over temperature) must be taken into account.
Note 6: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the
nominal reference voltage measured at 6V input. To express these thresholds in terms of output voltage change,
multiply by the error amplifier gain = V
OUT
/V
REF
= (R1 + R2)/R2. For example, at a programmed output voltage of 5V,
the Error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain
constant as a percent of V
OUT
as V
OUT
is varied, with the dropout warning occurring at typically 5% below nominal, 7.5%
guaranteed.
Note 7: V
SHUTDOWN
≥ 2V, V
IN
≤ 26V, V
OUT
= 0, Feedback pin tied to 5V/3.3V Tap.
