-5V/-12V/-15V or Adjustable,
High-Efficiency, Low I
Q
DC-DC Inverters
____________________________Typical Operating Characteristics (continued)
(V+ = 5V, V
OUT
= -5V, T
A
= +25°C, unless otherwise noted.)
DISCONTINUOUS CONDUCTION AT
HALF CURRENT LIMIT
CONTINUOUS CONDUCTION AT
FULL CURRENT LIMIT
MAX764/MAX765/MAX766
A
A
B
B
0A
0A
0V
C
0V
C
5µs/div
CIRCUIT OF FIGURE 2, V+ = 5V, V
OUT
= -5V, I
LOAD
= 80mA
A: OUTPUT RIPPLE, 100mV/div
B: INDUCTOR CURRENT, 500mA/div
C: LX WAVEFORM, 10V/div
5µs/div
CIRCUIT OF FIGURE 2, V+ = 5V, V
OUT
= -5V, I
LOAD
= 240mA
A: OUTPUT RIPPLE, 100mV/div
B: INDUCTOR CURRENT, 500mA/div
C: LX WAVEFORM, 10V/div
______________________________________________________________Pin Description
PIN
1
2
3
4
5
6, 7
8
NAME
OUT
FB
SHDN
REF
GND
V+
LX
FUNCTION
Sense Input for Fixed-Output Operation (V
FB
= V
REF
). OUT must be connected to V
OUT
.
Feedback Input. Connect FB to REF to use the internal voltage divider for a preset output. For adjustable-
output operation, use an external voltage divider, as described in the section
Setting the Output Voltage.
Active-High Shutdown Input. With SHDN high, the part is in shutdown mode and the supply current is less
than 5µA. Connect to ground for normal operation.
1.5V Reference Output that can source 100µA for external loads. Bypass to ground with a 0.1µF capacitor.
Ground
Positive Power-Supply Input. Must be tied together.
Place a 0.1µF input bypass capacitor as close to
the V+ and GND pins as possible.
Drain of the Internal P-Channel Power MOSFET. LX has a peak current limit of 0.75A.
_______________________________________________________________________________________
7
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
