Nov
SP6126
High-Voltage, Step Down Controller in TSOT6
LX
GND
FB
FEATURES
Wide 4.5V – 29V Input Voltage Range
Internal Compensation
Built-in High Current PMOS Driver
Adjustable Overcurrent Protection
Internal soft-start
600kHz Constant Frequency Operation
0.6V Reference Voltage
1% output setpoint accuracy
Lead Free, RoHS Compliant Package:
Small 6-Pin TSOT
6
5
4
SP6126
6 PinTSOT
1
V
IN
2
GATE
3
VDR
DESCRIPTION
The SP6126 is a PWM controlled step down (buck) voltage mode regulator with V
IN
feedforward and
internal Type-II compensation. It operates from 4.5V to 29V making is suitable for 5V, 12V, and 24V
applications. By using a PMOS driver, this device is capable of operating at 100% duty cycle. The
high side driver is designed to drive the gate 5V below V
IN
. The programmable overcurrent
protection is based on high-side MOSFET’s ON resistance sensing and allows setting the
overcurrent protection value up to 300mV threshold (measured from V
IN
-LX). The SP6126 is
available in a space-saving 6-pin TSOT package making it the smallest controller available capable
of operating from 24VDC supplies.
TYPICAL APPLICATION CIRCUIT
VIN
Q1
Si2343DS
2
1
Vin
Rs=1k
LX
C7
0.1uF
6
C4
22uF
R1
200k, 1%
4
VFB
GND
5
D1 1N4148
SHDN
High=Of f
2008 Exar Corporation
C1
10uF
12V
GND
Gate
L1, IHLP-2525CZ
6.8uH, 60mOhm, 4.5A
VOUT
3.3V
0-2.0A
SP6126
3
VDR
Ds
MBRA340T3G
RZ
2K
CZ
62pF
R2
44.2k, 1%
GND
Nov07-08
RevG
SP6126: TSOT-6 PFET Buck Controller
1
EXAR [ EXAR CORPORATION ]
