Pin description (continued) – Rainbow Electronics MAX34441 User Manual

Page 11

PMBus 5-Channel Power-Supply Manager

and Intelligent Fan Controller

MAX34441

Pin Description (continued)

Note: All pins except V

, V

, REG18, REG25, ADC, and the EP are high impedance with a 50µA pullup during device power-up

and reset. After device reset, the weak pullup is removed, and the pin is configured as input or output.

NAME

FUNCTION

PWM3

PWM Margin Output #3. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.

REG18

Regulator for Low-Voltage Digital Circuitry. Bypass REG18 to V

with 1FF and 10nF capacitors. Do

not connect other circuitry to this pin.

PSEN3

Power-Supply Enable Output #3. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.

PWM2

PWM Margin Output #2. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.

PSEN2

Power-Supply Enable Output #2. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.

PWM1

PWM Margin Output #1. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.

PSEN1

Power-Supply Enable Output #1. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.

PWM0

PWM Margin Output #0. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.

REG25

Regulator for Analog Circuitry. Bypass REG25 to V

with 1FF and 10nF capacitors. Do not connect

other circuitry to this pin.

PSEN0

Power-Supply Enable Output #0. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.

SDA

C/SMBus-Compatible Input/Output

SCL

C/SMBus-Compatible Clock Input

A0/MUXSEL

SMBus Address 0 Input/Multiplexer Control Output. This dual-function pin is sampled on device
power-up to determine the SMBus address; connect a 100kI resistor from this pin to either V

to set the address. After device power-up, this pin becomes an output that acts as voltage/

current selector for an external analog multiplexer. MUXSEL is low for voltage measurements and
high for current measurements.

FAULT

Active-Low, Open-Drain Fault Input/Output. This pin is asserted when one or more of the power supplies
in a global group are shut down due to a fault condition. Also, this pin is monitored and, when it is
asserted, all power supplies in a global group are shut down. This pin is used to provide hardware
control for power supplies in a global group across multiple devices. This output is unconditionally
deasserted when RST is asserted or the device is power cycled. This pin has a 50Fs deglitch filter.

CONTROL

Device Enable. Option through ON_OFF_CONFIG for active-low or active-high power-supply control.
This pin has a 50Fs deglitch filter.

A1/PG/

TACHSEL

SMBus Address 1 Input/Power-Good Output. This triple-function pin is sampled on device power-
up to determine the SMBus address; connect a 100kI resistor from this pin to either V

or V

set the address. After device power-up, this pin becomes an output that transitions high when all
the enabled power supplies are above their associated POWER_GOOD_ON thresholds. Alternately,
this pin can be programmed through MFR_MODE to select between two tachometers in dual-fan
applications.

ALERT

Active-Low, Open-Drain Alert Output

RS-5

Thermal Diode ADC Voltage Negative-Sense Input, Measurement Relative to RS+5

RS+5

Thermal Diode ADC Voltage Positive-Sense Input, Measurement Relative to RS-5

—

Exposed Pad (Bottom Side of Package). Connect EP to V