under light-load applications. The device operates with
input voltages from 3.5V to 36V, while using only 28FA
quiescent current at no load. The switching frequency
is resistor programmable from 220kHz to 2.2MHz and
can be synchronized to an external clock. The device’s
output voltage is available as 5V fixed or adjustable from
1V to 10V. The wide input voltage range along with its
ability to operate at 98% duty cycle during undervolt-
age transients make the device ideal for automotive and
industrial applications.
Under light-load applications, the FSYNC logic input
allows the device to either operate in skip mode for
reduced current consumption or fixed-frequency FPWM
mode to eliminate frequency variation to minimize EMI.
Fixed-frequency FPWM mode is extremely useful for
power supplies designed for RF transceivers where
tight emission control is necessary. Protection features
include cycle-by-cycle current limit and thermal shut-
down with automatic recovery. Additional features include
a power-good monitor to ease power-supply sequenc-
ing and a 180N out-of-phase clock output relative to the
internal oscillator at SYNCOUT to create cascaded power
supplies with multiple devices.
The device operates over the -40NC to +125NC
automotive temperature range and is available in 16-pin
(5mm x 5mm) TQFN-EP and 16-pin TSSOP-EP packages.
Benefits and Features
●
Integration and High-Switching Frequency Saves
Space
• Integrated 3.5A High-Side Switch
• Low-BOM-Count Current-Mode Control
Architecture
• Fixed Output Voltage with ±2% Accuracy (5V) or
Externally Resistor Adjustable (1V to 10V)
• 220kHz to 2.2MHz Switching Frequency with
Three Operation Modes (Skip Mode, Forced
Fixed-Frequency Operation, and External
Frequency Synchronization)
• Automatic LX Slew-Rate Adjustment for Optimum
Efficiency Across Operating Frequency Range
●
180° Out-of-Phase Clock Output at SYNCOUT
Enables Cascaded Power Supplies for Increased
Power Output
●
Spread-Spectrum Frequency Modulation Reduces
EMI Emissions
●
Wide Input Voltage Range Supports Automotive
Applications
• 3.5V to 36V Input Voltage Range (42V Tolerant)
• Enable Input Compatible from 3.3V Logic Level
to 42V
●
Robust Performance Supports Wide Range of
Automotive Applications
• -40°C to +125°C Automotive Temperature Range
• Thermal-Shutdown Protection
•
AEC-Q100 Qualified
●
Power-Good Output Allows Power-Supply
Sequencing
Applications
●
Point-of-Load Applications
●
Distributed DC Power Systems
●
Navigation and Radio Head Units
Ordering Information/Selector Guide
and
Typical
Application Circuit
appear at end of data sheet.
19-6868; Rev 5; 315
MAX16935
36V, 3.5A, 2.2MHz Step-Down Converter
with 28µA Quiescent Current
Absolute Maximum Ratings
SUP, SUPSW, LX, EN to PGND ............................-0.3V to +42V
SUP to SUPSW .....................................................-0.3V to +0.3V
BIAS to AGND .........................................................-0.3V to +6V
SYNCOUT, FOSC, COMP, FSYNC,
PGOOD, FB to AGND ........................ -0.3V to (V
BIAS
+ 0.3V)
OUT to PGND ........................................................-0.3V to +12V
BST to LX.................................................................-0.3V to +6V
AGND to PGND ...................................................-0.3V to + 0.3V
LX Continuous RMS Current ................................................3.5A
*As per JEDEC51 standard (multilayer board).
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.