NCP81233
www.onsemi.com
30
DETAILED DESCRIPTION
General
The NCP81233, a multi-phase synchronous buck
controller with an I
2
C interface, provides power
management solutions for applications supported by
DrMOS. It supports 1-, 2-, 3-, 4-, or 6-phase operation and
provides differential voltage and current sense, flexible
programming, and comprehensive protections.
Operation Modes
The number of operational phases is programmed at
CONFIG pin as shown in Table 10. All used phases are
paralleled together in output of power stage with a common
voltage-sense feedback. All input pins of current senses in
unused phases can be left float.
TABLE 10. CONFIG CONFIGURATION
CONFIG
R
CONFIG
Phase Number Phase Number
Float PWM1+PWM2+PWM3+PWM4+PWM5+PWM6 6
Short to GND PWM1+PWM2+PWM3+PWM4 4
33k PWM1+PWM2+PWM3 3
13k PWM1+PWM2 2
5.1k PWM1 1
Other control functions can be programmed at MODE1
pin and MODE2 pin as shown in Table 11 and Table 12.
TABLE 11. MODE 1 CONFIGURATION
MODE1
R
MODE1
OVP & UVP OVP Option
OCP, UVP,
OTP
Float
Enabled Recoverable
Hiccup
33 k Latch Off
20 k
Latch Off
Hiccup
13 k Latch Off
8.2 k
Disabled Disabled Latch Off
5.1 k
2.7 k
Hiccup
Short to GND
TABLE 12. MODE 2 CONFIGURATION
MODE2
R
MODE2
Regulation
Reference
PIN 27
Function
OTP Option
Float
VBOOT/VID VB_RST#
OTP1
33 k OTP2
20 k
PSI
OTP1
13 k OTP2
8.2 k
REFIN PSI OTP2
5.1 k
2.7 k
OTP1
Short to GND
In applications with an external analog reference input,
the device needs to be programmed at MODE2 pin to select
REFIN as the regulation reference. Once REFIN is selected
as the regulation reference, the command Vout_Command
through I
2
C interface won’t be proceeded and the readback
result of the command Read_VOUT is FFh.
