PAC5255
Power Application Controller
9. PIN DESCRIPTION
Table 4. Multi-Mode Power Manager and System Pin Description
PIN NAME
PIN NUMBER
TYPE
DESCRIPTION
Switching supply current sense input. Connect to the positive side of the current sense
resistor.
CSM
DRM
20
Analog
Switching supply driver output. Connect to the base or gate of the external power NPN or
n-channel MOSFET. See PAC User Guide and application notes.
23
EP
19
Analog
Power
Power
Exposed pad. Must be connected to VSS in a star ground configuration. Connect to a large
PCB copper area for power dissipation heat sinking.
EP (VSS)
REGO
System regulator output. Connect to VSYS directly or through an external power-dissipating
resistor.
Internally generated 1.8V core power supply. Connect a 2.2μF or higher value ceramic
capacitor from VCC18 to VSSA. See Figure 9-1. Power Supply Bypass Capacitor Routing
below.
VCC18
VCC33
VCCIO
2
5
Power
Power
Power
Internally generated 3.3V power supply. Connect a 2.2μF or higher value ceramic capacitor
from VCC33 to VSSA. See PCB layout note below.
Internally generated digital I/O power supply. Connect a 4.7μF or higher value ceramic
capacitor from VCCIO to VSSA. See Figure 9-1. Power Supply Bypass Capacitor Routing
below.
56
Switching supply controller supply input. Connect a 1μF or higher value ceramic capacitor,
or a 0.1μF ceramic capacitor in parallel with a 10μF or higher electrolytic capacitor from
VHM to VSSP. This pin requires good capacitive bypassing to VSSP, so the ceramic capacitor
must be connected with a shorter than 10mm trace from the pin. See Figure 9-1. Power
Supply Bypass Capacitor Routing below.
VHM
22
21
Power
Power
Main power supply. Provides power to the power drivers as well as voltage feedback path
for the switching supply. Connect a properly sized supply bypass capacitor in parallel with
a 0.1μF ceramic capacitor from VP pin to VSS for voltage loop stabilization. This pin
requires good capacitive bypassing to VSS, so the ceramic capacitor must be connected with
a shorter than 10mm trace from the pin. See See Figure 9-1. Power Supply Bypass
Capacitor Routing below.
VP
VSS
7
6
Power
Power
Power
Ground.
VSSA
VSSP
Analog ground. Connect to VSS in a star ground configuration.
Power ground. Connect to VSS in a star ground configuration.
24
5V system power supply. Connect a 4.7μF or higher value ceramic capacitor from VSYS to
VSSP. See Figure 9-1. Power Supply Bypass Capacitor Routing below.
VSYS
18
Power
XIN
57
1
Analog
Analog
Crystal oscillator driver input. Leave floating if unused.
Crystal oscillator driver output. Leave floating if unused.
XOUT
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Rev 1.10‒March 3, 2018
ACTIVE-SEMI [ ACTIVE-SEMI, INC ]
