2 Configuring Two TPSM8D6C24EVM-2V0 as a
Four-Phase Single Output Evaluation Module
In addition, two TPSM8D6C24EVM-2V0
evaluation modules can be combined with a four board to board interconnects, in addition
to common VIN and VOUT, to demonstrate a two module, four-phase design.
First, update both boards as if converting
them from a dual-output to a two-phase following the steps mentioned in Section 1. See Figure 1-1, Figure 1-2 and Figure 2-1 for visual reference.
Now, update board number one with the following changes:
Remove R32 (bottom) to make space for programming MSEL2_B for phase 02 of a
4-phase.
Install a 8.25-kΩ resistor in the R21
(bottom) location to configure Channel A as the leader (Phase 00) of a 4-phase
stack.
Install a 68.1-kΩ resistor in the R32
(bottom) location to configure Channel B as a phase 02 of a 4-phase stack. Note:
Channel B of board 1 is configured as Phase 02 rather than Phase 01 so that phases
within a single module operate 180 degrees out of phase with each other.
Add a small signal wire to the SYNC test point (TP15)
Add a small signal wire to the VSHAREA test point (TP12)
Add a small signal wire to one side of R19 (BCX_CLK)
Add a small signal wire to one side of R20 (BCX_DAT)
Figure 2-1 Bottom View of Four-Phase
Configuration
Update board number-two with the following changes:
Remove R12 (Bottom) to disconnect GOSNS/FLWR_A from the output ground
Remove R32 (Bottom) to make space for programming MSEL2_B for phase 03 of a
4-phase
Install a 10-kΩ resistor in the R5
(top) location to pull GOSNS/FLWR_A to BP1V5_A to configure channel A as a stack
follower.
Install a 6.81-kΩ resistor in the R21
(Bottom) location to configure Channel A as a Phase 01 follower of a 4-pahse
stack.
Install a 31.6-kΩ resistor in the R32
(Bottom) location to configure Channel A as a Phase 03 follower of a 4-phase
stack
Finally, connect the two boards together.
Add Short, Heavy Gauge wires (solid preferred) to PVIN_A, PVIN_B, VOUT_A, and VOUT_B
and GND terminals on both input and output sides of board two.
Tighten the terminal blocks.
Stack Board number 1 directly on top of board number two, and connect the wires to
the matching terminal blocks on board number one.
Tighten the terminal blocks on board number one
Solder the 4 small signal wires from board number one to the matching location on
board number two.
VSHARE_A to VSHARE_A (TP12)
SYNC to SYNC (TP15)
BCX_CLK (R19) to BCX_CLK (R19)
BCX_DAT (R20) to BCX_CLK (R20)
The two EVMs are now configured as a
single output 4-phase converter (Figure 1-1). Thanks to the BCX_CLK and BCX_DAT connections between the four
devices, the PMBus only needs to connect to EVM board one, which is placed on top to
allow access to the 10-pin connector for the USB-to-GPIO adapter.