MAX761EVKIT-SO Maxim Integrated, MAX761EVKIT-SO Datasheet - Page 3

• Manufacturer Part Number: MAX761EVKIT-SO
• Description: Power Management IC Development Tools
• Manufacturer: Maxim Integrated
• Series: MAX761, MAX762r

The MAX761 provides a SHDN pin to disable the out-
put. Table 1 lists the options available for the shutdown
control jumper, JU3. To use an external control signal,
remove the shunt on JU3 completely and connect the
external signal to the pad labeled SHDN. SHDN is a
TTL/CMOS-logic-level input.
Table 1. Jumper JU3 Functions
The MAX761 provides a low-battery comparator that
compares the voltage on LBI to the 1.5V reference volt-
age. LBO, an open-drain output, goes low when the LBI
Figure 1. MAX761 EV Kit Schematic
POSITION
SHUNT
1-2
2-3
LB0
LB1
OPEN
Connected to GND
Connected to V
R6
(PC TRACE)
SHDN PIN
OPEN
_______________________________________________________________________________________
R4
SHORT
OPEN
R3
R5
IN
Low-Battery Indicator
0.1μF
C3
Shutdown Control
1
MAX761 Enabled
V
Shutdown Mode
V
JU3
OUT
OUT
2
MAX761 OUTPUT
3
4
1
2
5
= 12V
= V
LBO
SHDN
LBI
REF
IN
- 0.3V
SHDN
MAX761
U1
GND
C1
22μF
20V
LX
V+
FB
MAX761 Evaluation Kit
18μH
voltage falls below V
voltage divider between the LBI pad and the MAX761 LBI
pin. Refer to the Low-Battery Detector section of the
MAX761 data sheet for instructions on selecting values
for R3 and R4. Note that the printed-circuit board (PCB)
trace across R3 shorts the LBI pin to ground when this
function is not used. Cut this trace before installing R3.
Install a 100kΩ pullup resistor between VIN (R5) or VOUT
(R6) if LBO is used. LBO is disabled in shutdown mode.
To adjust the output voltage, add output-voltage-divider
resistors R1 and R2 to either bootstrapped or nonboot-
strapped configurations. Refer to the Setting the Output
Voltage section in the MAX761 IC data sheet for
instructions on selecting values for R1 and R2. When
using output voltage-divider resistors, disconnect the
MAX761 feedback pin (FB) from ground by cutting the
thin PCB trace between the pads of JU1. Some users
may want to install a small (100pF to 200pF) capacitor
(C4) to increase light-load efficiency.
7
8
3
6
L1
C5
0.1μF
JU1
D1
JU2
Output-Voltage Adjustment
REF
OPEN
OPEN
R2
R1
V
2V to 12V
. Resistors R3 and R4 form a
V+
IN
C4
OPEN
C2
22μF
20V
V
12V
OUT
3