19-5673; Rev 0; 3/11
MAX16975
28V, 1.2A Automotive Step-Down Converter
with Low Operating Current
General Description
Features
The MAX16975 is a 1.2A current-mode step-down con-
verter with an integrated high-side switch. The device
operates with input voltages from 3.5V to 28V while using
only 45FA quiescent current at no load. The switching
frequency is adjustable from 220kHz to 1.0MHz by using
an external resistor, and can be synchronized to an exter-
nal clock. The device’s output voltage is pin-selectable to
a fixed 5V or adjustable from 1V to 10V using external
resistors. The wide input voltage range makes the device
ideal for automotive and industrial applications.
S Wide 3.5V to 28V Input Voltage Range
S 42V Input Transient Tolerance
S 5V Fixed or 1V to 10V Adjustable Output Voltage
S Integrated 1.2A High-Side Switch
S 220kHz to 1.0MHz Adjustable Switching Frequency
S Frequency Synchronization Input
S Internal Boost Diode
S 45µA Skip-Mode Operating Current
The device operates in skip mode for reduced current
consumption in light-load conditions. An adjustable
reset threshold helps keep microcontrollers alive down
to the lowest specified input voltage. Protection features
include cycle-by-cycle current limit, soft-start, overvolt-
age, and thermal shutdown with automatic recovery.
The device also features a power-good monitor to ease
power-supply sequencing.
S Less than 10µA Shutdown Current
S Adjustable Power-Good Output Level and Timing
S 3.3V Logic Level to 42V Compatible Enable Input
S Current-Limit, Thermal Shutdown, and
Overvoltage Protection
S -40°C to +125°C Automotive Temperature Range
Applications
The device operates over the -40°C to +125°C automo-
tive temperature range, and is available in 16-pin QSOP
and QSOP-EP packages.
Automotive
Industrial
Ordering Information appears at end of data sheet.
Typical Application Circuit
3.5V TO 28V
C
47µF
C
4.7µF
C
IN3
0.1µF
IN1
IN2
C
0.1µF
BST
SUP
SUPSW
BST
L1
10µH
V
= 1.25V AT
OUT
EN
1.2A AT 400kHz
LX
FSYNC
COMP
V
OUT
R
C
47µF
C
OUT2
47µF
FB1
OUT1
D1
25kI
C
COMP1
OUT
5600pF
C
COMP2
OPEN
MAX16975
RESETI
R
FOSC
R
COMP
12kI
61.9kI
V
BIAS
FOSC
R
FB2
FB
R
RES
100kI
10kI
BIAS
RES
C
BIAS
1µF
CRES
GND
C
PLACE C (0.1µF) RIGHT NEXT TO SUP.
IN3
CRES
1nF
For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/MAX16975.related
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1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.