SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1117 , MSPM0L1227 , MSPM0L1227-Q1 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
In 1/4 bias mode (and nonstatic mode LCDMX > 0), VA and VD swing between V1 (Vlcd) and V5. VA and VD waveforms are complimentary to each other. VC swings between (V2 and V4). VB is connected to V3 (Vlcd/2).
In order to generate these waveforms, 4 switch control waveforms are generated as shown in the diagram below. From these 4 waveforms, nonoverlapping switch control signals (*_PHASE1 and *_PHASE2) are generated.
As can be seen from the diagram above, VA and VC switch controls are similar and VB and VD switch controls are similar. Following table summarizes how the various switches in the switch matrix are controlled using these signals in 1/4 bias mode.
Switch |
Switch Control (Switch is closed when switch control is high) |
Description |
VA-V1 | VA-SW-CTRL-PHASE2 | Vlcd on VA |
VA-V5 | VA-SW-CTRL-PHASE1 | V5 on VA |
VB-V2 | Switch open in 1/4 bias mode | |
VB-V3 | Always closed in 1/4 bias mode. | Vlcd*1/2 on VB |
VB-V4 | Switch open in 1/4 bias mode | |
VB-VD | Open | |
VC-V4 | VC-SW-CTRL-PHASE1 | Vlcd*1/4 on VC |
VC-V2 | VC-SW-CTRL-PHASE2 | Vlcd*3/4 on VC |
VD-V1 | VD-SW-CTRL-PHASE2 | Vlcd on VD |
VD-V5 | VD-SW-CTRL-PHASE1 | V5 on VD |
VA-VSS | Switch closed, when LCDON is 0. | |
VB-VSS | Switch closed, when LCDON is 0. | |
VC-VSS | Switch closed, when LCDON is 0. | |
VD-VSS | Switch closed, when LCDON is 0. |