MIC2940A/2941A
Micrel
Electrical Characteristics
(MIC2941A Only)
Parameter
Reference Voltage
Conditions
Min
1.223
1.210
(Note 8)
1.204
20
Typical
1.235
Max
1.247
1.260
1.266
40
60
Units
V
V max
V
nA
Reference Voltage
Adjust Pin
Bias Current
Reference Voltage
Temperature
Coefficient
Adjust Pin Bias
Current Temperature
Coefficient
Shutdown Input
Input Logic Voltage
20
ppm/°C
0.1
nA/°C
1.3
Low (ON)
High (OFF)
0.7
2.0
30
50
100
600
750
30
60
V
Shutdown Pin
Input Current
V
SHUTDOWN
= 2.4V
µA
V
SHUTDOWN
= 26V
Regulator Output
Current in Shutdown
(Note 10)
450
µA
µA
3
Note 1:
Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not
apply when operating the device outside of its rated operating conditions. The maximum allowable power dissipation is a function of the
maximum junction temperature, T
J (MAX)
, the junction-to-ambient thermal resistance,
θ
JA
, and the ambient temperature, T
A
. The maximum
allowable power dissipation at any ambient temperature is calculated using: P
(MAX)
= (T
J(MAX)
– T
A
) /
θ
JA.
Exceeding the maximum allowable
power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown.
Note 2:
Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 3:
Regulation is measured at constant junction temperature using low duty cycle pulse testing. Changes in output voltage due to
heating effects are covered by the thermal regulation specification.
Note 4:
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 low values of programmed output voltage, the minimum input supply voltage of 4.3V over temperature must
be taken into account.
Note 5:
Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current plus
the ground pin current.
Note 6:
The MIC2940A features fold-back current limiting. The short circuit (V
OUT
= 0V) current limit is less than the maximum current with
normal output voltage.
Note 7:
Thermal regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding
load or line regulation effects. Specifications are for a 200mA load pulse at V
IN
= 20V (a 4W pulse) for T = 10ms.
Note 8:
V
REF
≤
V
OUT
≤
(V
IN
– 1 V), 4.3V
≤
V
IN
≤
26V, 5mA < I
L
≤
1.25A, T
J
≤
T
J MAX.
Note 9:
Circuit of Figure 3 with R1
≥
150kΩ. V
SHUTDOWN
≥
2 V and V
IN
≤
26 V,V
OUT
= 0.
Note 10:
When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode
clamped to ground.
Note 11:
Maximum positive supply voltage of 60 V must be of limited duration (< 100 ms) and duty cycle (
≤
1%). The maximum continuous
supply voltage is 26V.
MIC2940A/2941A
4
June 1999
MICREL [ MICREL SEMICONDUCTOR ]
