MIC7401 Datasheet, PDF (8/68 Pages) Micrel Semiconductor – Configurable PMIC, Five-Channel Buck Regulator plus One-Boost with HyperLight Load®, I2C Control, and Enable

Micrel, Inc.
MIC7401
Pin Description (Continued)
Pin Number
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Pin Name
SW4
PGND4
OUT4
STBY
SDA
AGND
SCL
POR
OUT5
PGND5
SW5
PVIN5
OUT6
PGND6
SW6
Description
Switch Pin 4 (Output): Inductor connection for the synchronous step-down regulator. Connect the
inductor between the output capacitor and the SW4 pin.
Power Ground 4: The power ground for the synchronous buck converter power stage. The PGND pin
connects to the source of the internal low-side N-Channel MOSFET, the negative terminals of input
capacitors, and the negative terminals of output capacitors.
Output Voltage Sense 4 (Input): This pin is used to sense the output voltage. Connect the OUT4 as
close to the output capacitor as possible to sense output voltage. Also provides the path to discharge
the output through an internal 90Ω resistor when disabled. This pull-down feature is programmed
through the PULLD[x] register.
Standby Reset (Input): Standby mode allows the total power consumption to be reduced by either
lowering a supply voltage or turning it off. The IC can be placed in standby mode while operating in
normal mode by a high-to-low transition (DEFAULT) on the STBY input. When this occurs, the
STBY_MODEB bit will be set to logic “0”. Either a low-to-high transition on the STBY pin or an I²C
write command to the STBY_MODEB bit sets all of the regulators to their normal mode default
settings. This pin can be driven with either a digital signal or open collector output. Do not let this pin
float. Connect to ground or VIN. A pull-down resistor of 100kΩ or less can also be used. There are
both a high-to-low (DEFAULT) and low-to-high normal to standby trigger options available.
High-Speed Mode 3.4MHz I²C Data (Input/Output): This is an open drain, bidirectional data pin. Data
is read on the rising edge of the SCL and data is clocked out on the falling edge of the SCL. External
pull-up resistors are required.
Analog Ground: Internal signal ground for all low power circuits. Connect to ground plane for best
operation.
High-Speed Mode 3.4MHz I²C Clock (Input): I²C serial clock line open drain input. External pull-up
resistors are required.
Power-on-Reset (Output): This is an open drain output that goes high after the POR delay time
elapses. The POR delay time starts as soon as the AVIN pin voltage rises above the upper threshold
set by the PORUP register. The POR output goes low without delay when AVIN falls below the lower
threshold set by the PORDN register.
Output Voltage Sense 5 (Input): This pin is used to sense the output voltage. Connect OUT5 as close
to the output capacitor as possible to sense output voltage. Also provides the path to discharge the
output through an internal 90Ω resistor when disabled. This pull-down feature is programmed through
the PULLD[x] register.
Power Ground 5: The power ground for the synchronous buck converter power stage. The PGND pin
connects to the source of the internal low-side N-Channel MOSFET, the negative terminals of input
capacitors, and the negative terminals of output capacitors.
Switch Pin 5 (Output): Inductor connection for the synchronous step-down regulator. Connect the
inductor between the output capacitor and the SW5 pin.
Power Supply Voltage 5 (Input): Input supply to the source of the internal high-side P-channel
MOSFET. An input capacitor between PVIN5 and the power ground PGND5 pin is required and to be
placed as close as possible to the IC.
Output Voltage 6 Sense (Input): This pin is used to sense the output voltage. Connect OUT6 as close
to the output capacitor as possible to sense output voltage. Also provides the path to discharge the
output through an internal programmable current source when disabled. This pull-down feature is
programmed through the PULLD[x] register.
Power Ground 6: The power ground for the boost converter power stage. The PGND pin connects to
the source of the internal low-side N-Channel MOSFET, the negative terminals of input capacitors,
and the negative terminals of output capacitors.
Switch Pin 6 (Input): Inductor connection for the boost regulator. Connect the inductor between the
PVIN6O and SW6 pin.
March 16, 2015
8
Revision 1.0