MCP1825/MCP1825S
AC/DC CHARACTERISTICS (CONTINUED)
Electrical Specifications:
Unless otherwise noted, V
IN
= V
OUT(MAX)
+ V
DROPOUT(MAX)
,
Note 1,
V
R
= 1.8V for Adjustable Output,
I
OUT
= 1 mA, C
IN
= C
OUT
= 4.7 µF (X7R Ceramic), T
A
= +25°C.
Boldface
type applies for junction temperatures, T
J
(Note
7)
of
-40°C to +125°C
Parameters
Power Supply Ripple Rejection
Ratio
Sym
PSRR
Min
—
Typ
60
Max
—
Units
dB
Conditions
f = 100 Hz, C
OUT
= 4.7 µF,
I
OUT
= 100 µA,
V
INAC
= 100 mV pk-pk,
C
IN
= 0 µF
I
OUT
= 100 µA, V
OUT
= 1.8V,
V
IN
= 2.8V
I
OUT
= 100 µA, V
OUT
= 1.8V,
V
IN
= 2.8V
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Note 1:
2:
3:
4:
5:
6:
T
SD
ΔT
SD
—
—
150
10
—
—
°C
°C
7:
The minimum V
IN
must meet two conditions: V
IN
≥
2.1V and V
IN
≥
V
OUT(MAX)
+
V
DROPOUT(MAX).
V
R
is the nominal regulator output voltage for the fixed cases. V
R
= 1.2V, 1.8V, etc. V
R
is the desired set point output
voltage for the adjustable cases. V
R
= V
ADJ *
((R
1
/R
2
)+1).
Figure 4-1.
TCV
OUT
= (V
OUT-HIGH
– V
OUT-LOW
) *10
6
/ (V
R
*
ΔTemperature).
V
OUT-HIGH
is the highest voltage measured over the
temperature range. V
OUT-LOW
is the lowest voltage measured over the temperature range.
Load regulation is measured at a constant junction temperature using low duty-cycle pulse testing. Load regulation is
tested over a load range from 1 mA to the maximum specified output current.
Dropout voltage is defined as the input-to-output voltage differential at which the output voltage drops 2% below its
nominal value that was measured with an input voltage of V
IN
= V
OUT(MAX)
+ V
DROPOUT(MAX)
.
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction
temperature and the thermal resistance from junction to air. (i.e., T
A
, T
J
,
θ
JA
). Exceeding the maximum allowable power
dissipation will cause the device operating junction temperature to exceed the maximum +150°C rating. Sustained
junction temperatures above 150°C can impact device reliability.
The junction temperature is approximated by soaking the device under test at an ambient temperature equal to the
desired junction temperature. The test time is small enough such that the rise in the junction temperature over the
ambient temperature is not significant.
©
2008 Microchip Technology Inc.
DS22056B-page 9
MICROCHIP [ MICROCHIP TECHNOLOGY ]
