Datasheet
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
7Maxim Integrated
Pin Descriptions (continued)
Detailed Description
The MAX16962 is a high-efficiency, synchronous step-
down converter that operates with a 2.7V to 5.5V input
voltage range and provides a 0.8V to 3.6V output voltage
range. The MAX16962 delivers up to 4A of load current
and achieves -3.7%/+2.6% output error over load, line,
and temperature ranges.
The PWM input forces the MAX16962 into either a fixed-
frequency, 2.2MHz PWM mode or a low-power pulse
frequency modulation mode (SKIP). Optional spread-
spectrum frequency modulation minimizes radiated elec-
tromagnetic emissions due to the switching frequency.
The factory programmable synchronization I/O (SYNC)
enables system synchronization.
Integrated low R
DSON
switches help improve efficiency
at heavy loads and make the layout a much simpler task
with respect to discrete solutions.
The device is offered with factory-preset output volt-
ages that achieve -3.7%/+2.6% output voltage accuracy
without using external resistors. In addition, the output
voltage can be set to any desired values between 0.8V
to 3.6V using an external resistive divider wth the adjust-
able option.
Additional features include 8ms soft-start, 16ms power-
good delay output, overcurrent, and overtemperature
protections. See Figure 1.
Power-Good Output
The MAX16962 features an open-drain power-good out-
put that asserts when the output voltage drops 8% below
or rises 10% above the regulated voltage. PG remains
asserted for a fixed 16ms timeout period after the output
rises up to its regulated voltage. Connect PG to OUTS
with a 20kI resistor.
Soft-Start
The MAX16962 includes an 8ms fixed soft-start time.
Soft-start time limits startup inrush current by forcing the
output voltage to ramp up over time towards its regula-
tion point.
Spread-Spectrum Option
The MAX16962 featuring spread-spectrum (SS) opera-
tion varies the internal operating frequency up by
SS = 6% relative to the internally generated operating
frequency of 2.2MHz (typ). This function does not apply
to externally applied oscillation frequency. The internal
oscillator is frequency modulated with a 6% frequency
deviation. See the Selector Guide for available options.
Synchronization (SYNC)
SYNC is a factory-programmable I/O. See the Selector
Guide for available options. When SYNC is configured
as an input, a logic-high on PWM enables SYNC to
accept signal frequency in the range of 1.7MHz < f
SYNC
< 2.4MHz. When SYNC is configured as an output, a
logic-high on PWM enables SYNC to output a 90N
phase-
shifted signal with respect to internal oscillator.
Current-Limit/Short-Circuit Protection
The MAX16962 features current limit that protects the
device against short-circuit and overload conditions at
the output. In the event of a short-circuit or overload
condition, the high-side MOSFET remains on until the
inductor current reaches the high-side MOSFET’s cur-
rent-limit threshold. The converter then turns on the low-
side MOSFET to allow the inductor current to ramp down.
Once the inductor current crosses the low-side MOSFET
current-limit threshold, the converter turns on the high-
side MOSFET for minimum on-time periode. This cycle
repeats until the short or overload condition is removed.
PIN
NAME FUNCTION
TQFN TSSOP
12 14 PV
Device Supply Voltage Input. Bypass with at least a 1FF ceramic capacitor to GND. In addition,
connect a 10I decoupling resistor between PV and the bypass capacitor.
16 2 PV2
Input Supply 2. Bypass PV2 with at least a 4.7FF ceramic capacitor to PGND2. Connect PV2 to
PV1 for normal operation.
— — EP
Exposed Pad. Connect EP to a large-area contiguous copper ground plane for effective power
dissipation. Do not use as the only IC ground connection. EP must be connected to GND.