MAX17112 Datasheet, PDF (6/12 Pages) Maxim Integrated Products – High-Performance, Step-Up, DC-DC Converter

High-Performance, Step-Up, DC-DC Converter
Pin Description
PIN
NAME
FUNCTION
1
COMP
Compensation Pin for Error Amplifier. Connect a series RC from COMP to ground. Typical values
are 47k
and 580pF.
2
FB
Feedback. The FB regulation voltage is 1.24V nominal. Connect an external resistor-divider center
tap here and minimize the trace area. Set V_OUT according to the Output Voltage Selection section.
3
V_L
IC Supply. There is an internal switch between IN and V_L and the switch disconnects when an
overvoltage condition on IN is detected. Bypass V_L to GND with a 1μF capacitor.
4, 5
GND
Ground
6, 7
LX
Switch. LX is the drain of the internal MOSFET.
8
IN
Supply Voltage Input. Bypass IN with a minimum 1μF ceramic capacitor directly to GND.
Shutdown Control Input. Drive SHDN high to turn on the MAX17112 for normal operation. Connect a
9
SHDN
capacitor to the SHDN pin to create a delayed turn-on. The time delay is 0.25 x C (typ), C in
microfarads. SHDN can be driven from a logic signal directly, in which case a resistor is required
in series with SHDN.
10
SS
Soft-Start Control. Connect a soft-start capacitor (C_SS). Leave open for no soft-start. The soft-start
capacitor is charged at a rate of 4μA/C_SS.
—
EP
Exposed Pad. Connect to GND.
V_IN
4.5V TO 5.5V
L1
2.7μH
D1
V_OUT
+15V/600mA
C1
4.7μF
10V
C2
4.7μF
10V
C10
1μF
C3
1μF
C9
1μF
C4
3.3nF
8 _IN
U1
MAX17112
9 _SHDN
3 _VL
10 _SS
COMP
1
LX ⁶
LX ⁷
GND ⁵
4
GND
FB ²
GND ^EP
C7
C8
10μF
10μF
25V
25V
R4
221kΩ
R3
20kΩ
R2
47kΩ
C5
560pF
C6
OPEN
Figure 1. Typical Operating Circuit
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