ISL6377 Datasheet, PDF (18/36 Pages) Intersil Corporation – Multiphase PWM Regulator for AMD Fusion™ Desktop CPUs Using SVI 2.0

ISL6377
REP RATE = 10kHz
REP RATE = 25kHz
REP RATE = 50kHz
REP RATE = 100kHz
REP RATE = 200kHz
FIGURE 16. CURRENT BALANCING DURING DYNAMIC OPERATION.
CH1: I_L1, CH2: I_LOAD, CH3: I_L2, CH4: I_L3
Modes of Operation
TABLE 1. CORE VR MODES OF OPERATION
CONFIG. ISEN4 ISEN3 ISEN2 PSI0_L & PSI1_L MODE
4-phase To Power To Power To Power
Core VR Stage Stage Stage
Config.
11
4-phase CCM
01
2-phase CCM
00
1-phase DE
3-phase Tied to 5V To Power To Power
Core VR
Stage Stage
Config.
11
3-phase CCM
01
2-phase CCM
00
1-phase DE
2-phase Tied to 5V Tied to 5V To Power
Core VR
Stage
Config.
11
2-phase CCM
01
1-phase CCM
00
1-phase DE
1-phase Tied to 5V Tied to 5V Tied to 5V
11
1-phase CCM
Core VR
Config.
01
1-phase CCM
00
1-phase DE
The Core VR can be configured for 4-, 3-, 2- or 1-phase operation.
Table 1 shows Core VR configurations and operational modes,
programmed by the ISEN4, ISEN3 and ISEN2 pin status and the
PSI0_L & PSI1_L commands via the SVI 2 interface. The SVI 2
interface description of these bits is outlined in Table 9.
The ISENx pins disable the channel which they are related. For
example, to setup a 3-phase configuration the ISEN4 pin is tied to
5V. This disables Channel 4 of the controller on the Core side.
In a 3-phase configuration, the Core VR operates in 3-phase CCM,
with PSI0_L and PSI_L both high. If PSI0_L is taken low via the
SVI 2 interface, the Core VR sheds Phase 3. The Core VR then
operates 2-Phase and remains in CCM. When both PSI0_L and
PSI1_L are taken low, the Core VR sheds Phase 2 and the Core
VR enters 1-Phase Diode Emulation (DE) mode.
For 2-phase configurations, the Core VR operates in 2-phase CCM
with PSI0_L and PSI_L both high. If PSI0_L is taken low via the
SVI 2 interface, the Core VR sheds Phase 2 and the Core VR
operates in 1-phase and remains in CCM. When both PSI0_L and
PSI1_L are taken low, the Core VR operates in 1-phase DE mode.
In a 1-phase configuration, the Core VR operates in 1-phase CCM
and remains in this mode when PSI0_L is taken low. When both
PSI0_l and PSI1_L are taken low, the controller enters DE mode.
The Core VR can be disabled completely by connecting ISEN1 to +5V.
ISL6377 Northbridge VR can be configured for 2- or 1-phase
operation. Table 2 shows the Northbridge VR configurations and
operational modes, which are programmed by the ISEN2_NB pin
status and the PSI0_L and PSI1_L bits of the SVI 2 command.
TABLE 2. NORTHBRIDGE VR MODES OF OPERATION
CONFIG.
ISEN2_NB PSI0_L & PSI1_L MODE
2-phase NB VR Config. To Power Stage
11
2-phase CCM
01
1-phase CCM
00
1-phase DE
1-phase NB VR Config. Tied to 5V
11
1-phase CCM
01
1-phase CCM
00
1-phase DE
18
FN8336.0
August 6, 2012