NCP81245
www.onsemi.com
6
Table 1. QFN52 PIN LIST DESCRIPTION
Pin Name Description
1 VSP_3PH_A Differential output voltage sense positive for multi−phase rail “A”
2 VSN_3PH_A Differential output voltage sense negative for multi−phase rail “A”
3 IMON_3PH_A
A resistor to ground programs IOUT gain for multi−phase rail “A”
4 DIFFOUT_3PH_A Output of multi−phase rail “A” differential remote sense amplifier
5 FB_3PH_A Error amplifier voltage feedback for multi−phase rail “A”
6 COMP_3PH_A Error amplifier output and PWM comparator inverting input for multi−phase rail “A”
7 ILIM_3PH_A A resistor to CSCOMP_3PH_A programs the over−current threshold for multi−phase rail “A”
8 CSCOMP_3PH_A Total−current−sense amplifier output for multi−phase rail “A”
9 CSSUM_3PH_A Inverting input of total−current−sense amplifier for multi−phase rail “A”
10 CSREF_3PH_A Total−current−sense amplifier reference voltage input for multi−phase rail “A”
11 CSP1_3PH_A Current−balance amplifier positive input for Phase 1 of multi−phase rail “A”
12 CSP2_3PH_A Current−balance amplifier positive input for Phase 2 of multi−phase rail “A”
13 CSP3_3PH_A Current−balance amplifier positive input for Phase 3 of multi−phase rail “A”
14 TTSENSE_3PH_A Temperature sense input for multi−phase rail “A”
15 VRMP Vin feed−forward input. Controls a current used to generate the ramps of the modulators
16 VCC Power for the internal control circuits. A decoupling capacitor is connected from this pin to ground
17 DRON External FET driver enable for discrete driver or DrMOS
18 PWM1_3PH_A /
ICCMAX_3PH_A
Phase 1 PWM output of multi−phase rail “A” /
A resistor to ground programs ICCMAX for multi−phase rail “A”
19 PWM2_3PH_A /
ADDR
Phase 2 PWM output of multi−phase rail “A” /
A resistor to ground configures Intel proprietary interface addresses for all 3 rails (ADDR)
20 PWM3_3PH_A /
VBOOT
Phase 3 PWM output of multi−phase rail “A” /
A resistor to ground configures boot voltage for all 3 rails (VBOOT)
21 PWM3_3PH_B /
ROSC_3PH
Phase 3 PWM output of multi−phase rail “B” / Phase 4 PWM output of multi−phase rail “A” /
A resistor to ground configures Fsw for both “A” and “B” multi−phase rails (ROSC_3PH)
22 PWM2_3PH_B /
ROSC_1PH
Phase 2 PWM output of multi−phase rail “B” /
A resistor to ground configures Fsw for 1ph rail (ROSC_1ph)
23 PWM1_3PH_B /
ICCMAX_3PH_B
Phase 1 PWM output of multi−phase rail “B” /
A resistor to ground programs ICCMAX for multi−phase rail “B”
24 TTSENSE_1PH /
PSYS
Temperature sense input for the single−phase rail /
System input power monitor. A resistor to ground scales this signal
25 TTSENSE_3PH_B Temperature sense input for multi−phase rail “B”
26 CSP3_3PH_B Current−balance amplifier positive input for Phase 3 of multi−phase rail “B” / Phase 4 of multi−phase
rail “A”
27 CSP2_3PH_B Current−balance amplifier positive input for Phase 2 of multi−phase rail “B”
28 CSP1_3PH_B Current−balance amplifier positive input for Phase 1 of multi−phase rail “B”
29 CSREF_3PH_B Total−current−sense amplifier reference voltage input for multi−phase rail “B”
30 CSSUM_3PH_B Inverting input of total−current−sense amplifier for multi−phase rail “B”
31 CSCOMP_3PH_B Total−current−sense amplifier output for multi−phase rail “B”
32 ILIM_3PH_B A resistor to CSCOMP_3PH_B programs the over−current threshold for multi−phase rail “B”
33 COMP_3PH_B Error amplifier output and PWM comparator inverting input for multi−phase rail “B”
34 FB_3PH_B Error amplifier voltage feedback for multi−phase rail “B”
35 DIFFOUT_3PH_B Output of multi−phase rail “B” differential remote sense amplifier
36 IMON_3PH_B A resistor to ground programs IOUT gain for multi−phase rail “B”
37 VSN_3PH_B Differential output voltage sense negative for multi−phase rail “B”
