Datasheet

MAX774/MAX775/MAX776
-5V/-12V/-15V or Adjustable, High-Efficiency,
Low I
Q
Inverting DC-to-DC Controllers
8 _______________________________________________________________________________________
______________________________________________________________Pin Description
PIN NAME FUNCTION
1 OUT
2 FB
3 SHDN
4 REF 1.5V reference output that can source 100µA. Bypass to ground with 0.1µF.
5 V+ Positive power-supply input
6 CS Noninverting input to the current-sense comparator. Typical trip level is 210mV (relative to V+).
7 EXT The gate-drive output for an external P-channel power MOSFET. EXT swings from OUT to V+.
8 GND Ground
The sense input for fixed-output operation (V
FB
= V
REF
). OUT is connected to the internal voltage divider,
and it is the negative supply input for the EXT driver.
Feedback input. When V
FB
= V
REF
, the output will be the factory preset value. For adjustable operation,
use an external voltage divider, as described in the Adjustable Output section.
Active-high shutdown input. With SHDN high, the part is in shutdown mode and the supply current is less
than 5µA. Connect to GND for normal operation.
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
CIRCUIT OF FIGURE 2
V+ = 6V, V
OUT
= -5V
A: I
LOAD
, 30mA TO 1A, 1A/div
B: V
OUT
, 100mV/div, AC-COUPLED
LOAD-TRANSIENT RESPONSE
100µs/div
A
B
CIRCUIT OF FIGURE 2
V
OUT
= -5V, I
LOAD
= 1A
A: V+, 3V TO 8V, 5V/div
B: V
OUT
, 100mV/div, AC-COUPLED
LINE-TRANSIENT RESPONSE
2ms/div
A
B