184.108.40.206 Step-Down Converters SMPS1, SMPS2 or SMPS1&2
The step-down converters, SMPS1 and SMPS2, can be used in two different configurations which are described as follows:
- SMPS1 and SMPS2 in single-phase configuration with each SMPS supporting a 3.5-A load current
- SMPS1&2 in dual-phase configuration supporting 7-A load current
SMPS1 and SMPS2 can be used as separate converters. In dual-phase configuration the two interleaved synchronous buck-regulator phases with built-in current sharing operate in opposite phases. For light loads, the converter automatically changes to single-phase operation.
Figure 5-14 shows the connections for dual-phase configurations.
Figure 5-14 SMPS1&2 Dual-Phase Configuration
Below are the steps to program the SMPS1 and SMPS2 for single-phase or dual-phase operation:
- The OTP bit defines single-phase (SMPS1 and SMPS2) or dual-phase (SMPS1&2) operation. If dual-phase mode is selected, the SMPS12 registers control SMPS1&2.
- By default, SMPS1&2 operates in dual-phase mode for higher load currents and switches automatically to single-phase mode for low load currents. Forcing multiphase operation or single-phase operation is possible by setting the SMPS_CTRL.SMPS12_PHASE_CTRL[1:0] bits when the SMPS1&2 are loaded. Under no-load condition, do not force the multiphase operation because it causes SMPS12 to exhibit instability.