Datasheet

MCP2021/2/1P/2P
DS22018F-page 8 © 2005-2012 Microchip Technology Inc.
FIGURE 1-2: MCP2021/2 Operational Modes State Diagrams.
FIGURE 1-3: MCP2021P/2P Operational Modes State Diagrams.
Power-Down
TX: OFF
RX: OFF
VREG: OFF
CS/LWAKE=0
Transmitter Off
TX: OFF
RX: ON
VREG: ON
POR
TX: OFF
RX: OFF
VREG: OFF
Operation
TX: ON
RX: ON
VREG: ON
Ready
TX: OFF
RX: ON
VREG: ON
VBAT
>
5
.
75
V
CS/LWAKE=1&
VREG_OK=1
CS/LWAKE=0
FAULT/TXE=0
Or Faults*
FAULT/TXE=1
&No Faults*
CS/LWAKE=1
or dominant level on LBUS
Start
*Fault: thermal shutdown and TXD/LBUS permanent dominant
Note: While the device is in shutdown, TXD should not be actively driven high or it may power internal logic
through the ESD diodes and may damage the device.
Power-Down
TX: OFF
RX: OFF
VREG: OFF
CS/LWAKE=0
Transmitter Off
TX: OFF
RX: ON
VREG: ON
POR
TX: OFF
RX: OFF
VREG: OFF
Operation
TX: ON
RX: ON
VREG: ON
Ready
TX: OFF
RX: ON
VREG: ON
VBAT
>
5
.
75
V
CS/LWAKE=1&
VREG_OK=1&
FAULT/TXE=1
CS/LWAKE=0
FAULT/TXE=0
Or Faults*
FAULT/TXE=1
&No Faults*
CS/LWAKE=1
or Falling edge on LBUS
Start
*Fault: thermal shutdown and TXD/LBUS permanent dominant
CS=1&VREG_OK=1
&FAULT/TXE=0