Datasheet

MCP2120
DS21618B-page 20 © 2007 Microchip Technology Inc.
FIGURE 4-6: USART ASynchronous Transmission Waveform
TABLE 4-6: USART ASYNCHRONOUS TRANSMISSION REQUIREMENTS
AC Characteristics
Standard Operating Conditions (unless otherwise specified)
Operating Temperature –40°C ≤ T
A ≤ +85°C (industrial)
Operating Voltage V
DD range is described in Section 4.1 “DC
Characteristics”
Param.
No.
Sym Characteristic Min Typ Max Units Conditions
IR100 T
TXBIT Transmit Baud rate Hardware Selection
768 — 768 T
OSC BAUD2:BAUD0 = 000
384 — 384 T
OSC BAUD2:BAUD0 = 001
192 — 192 TOSC BAUD2:BAUD0 = 010
128 — 128 T
OSC BAUD2:BAUD0 = 011
64 — 64 T
OSC BAUD2:BAUD0 = 100
Software Selection
BAUD2:BAUD0 = 111
768 — 768 T
OSC Hex Command = 0x87
384 — 384 T
OSC Hex Command = 0x8B
192 — 192 T
OSC Hex Command = 0x85
128 — 128 TOSC Hex Command = 0x83
64 — 64 T
OSC Hex Command = 0x81
IR101 E
TXBIT Transmit (TX pin) Baud rate
Error (into MCP2120)
——1%
IR102 E
TXIRBIT Transmit (TXIR pin) Baud rate
Error (out of MCP2120)
(1)
——1%
IR103 T
TXRF TX pin rise time and fall time — — 25 ns
Note 1: This error is not additive to IR101 parameter.
Note: Refer to Figure 4-2 for load conditions.
IR103
TX pin
IR100
IR103
IR100 IR100 IR100
Start Bit Data Bit Data Bit Data Bit