Datasheet

High-Voltage, 2.2MHz, 2A Automotive Step-
Down Converter with Low Operating Current
MAX16974
10 _____________________________________________________________________________________
Detailed Description
The MAX16974 is a constant-frequency, current-mode,
automotive buck converter with an integrated high-side
switch. The device operates with 3.5V to 28V input volt-
ages and tolerates input transients up to 42V. During
undervoltage events, such as cold-crank conditions, the
internal pass device maintains up to 92% duty cycle.
An open-drain, active-low reset output helps monitor the
output voltage. The device offers an adjustable reset
threshold that helps keep microcontrollers alive down
to their lowest specified input voltage. A capacitor pro-
grammable reset timeout ensures proper startup.
The switching frequency is resistor programmable from
220kHz to 2.2MHz to allow optimization for efficiency,
noise, and board space. A clock input, FSYNC, allows
the device to synchronize to an external clock.
During light-load conditions, the device enters skip
mode that reduces the quiescent current down to 35FA.
The 5V fixed output voltage option eliminates the need
for external resistors and reduces the supply current by
up to 50FA. See Figure 2 for the internal block diagram.
Supply Voltage Range (SUP)
The device’s supply voltage range (V
SUP
) is compatible
with the typical 3.5V to 28V automotive battery voltage
range and can tolerate transients up to 42V.
Figure 2. Internal Block Diagram
10µA
COMP
COMP
GND
B.G.
REF
SOFT-
START
UVLO
MUX
LDO
STANDBY
SUPPLY
REF
EA
LOGIC FOR
DROPOUT
RES
V
BIAS
FB
RESETI
CRES
PWM
COMP
LEVEL
SHIFT
I
LIM
LOGIC
EN
OSC
SUM
I
SENSE
FSYNC
FOSCBIASSUP
OUT
COMP
DRV
LX
BST SUPSW
MAX16974