March 2001 5 MIC29150/29300/29500/29750
MIC29150/29300/29500/29750 Micrel
Notes
Note 1: Maximum positive supply voltage of 60V must be of limited duration (<100msec) and duty cycle (≤1%). The maximum continuous supply
voltage is 26V.
Note 2: Full Load current (I
FL
) is defined as 1.5A for the MIC29150, 3A for the MIC29300, 5A for the MIC29500, and 7.5A for the MIC29750 families.
Note 3: Dropout voltage is defined as the input-to-output differential when the output voltage drops to 99% of its nominal value with V
OUT
+ 1V applied
to V
IN
Note 4: V
IN
= V
OUT (nominal)
+ 1V. For example, use V
IN
= 4.3V for a 3.3V regulator or use 6V for a 5V regulator. Employ pulse-testing procedures to
minimize temperature rise.
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: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
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), 2.3V ≤ V
IN
≤ 26V, 10mA < I
L
≤ I
FL
, T
J
≤ T
J MAX.
Note 9: Comparator thresholds are expressed in terms of a voltage differential at the Adjust 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/1.240 V = 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,
7.7% guaranteed.
Note 10: V
EN
≤ 0.8V and V
IN
≤ 26V, V
OUT
= 0.
Note 11: 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.
Block Diagram
Reference
28V
O.V.
I
LIMIT
Thermal
Shut-
down
1.240V
1.180V
EN
IN
FLAG
GND
OUT
ADJ
†
R1*
R2*
* Feedback network in fixed versions only
†
Adjustable version only
Typical Applications
Figure 1. Fixed output voltage. Figure 2. Adjustable output voltage configuration. For
best results, the total series resistance should be small
enough to pass the minimum regulator load current.
MIC29500-3.3
V ± 5%
47µF
3.3V ± 1% @ 5A
R1
R2
V
OUT
= 1.240V
× [1 + (R1 / R2)]
V
IN
V
OUT
