MCP2122

DS21894B-page 22

Preliminary

 2004 Microchip Technology Inc.

FIGURE 4-6:

TX AND TXIR WAVEFORMS

TABLE 4-6:

TX AND TXIR REQUIREMENTS

AC Characteristics

Standard Operating Conditions (unless otherwise specified)

Operating Temperature: –40

Section 4.1 “DC Characteristics”.

Param.

No.

Sym

Characteristic

Min

Max

Units

Conditions

IR100A

Transmit Baud Rate

—

16

—

IR100B

Transmit Baud Rate

16

—

16

IR102A

Host UART TX Error

—

—

± 2

%

Note 2, 3

IR102B

TXIR Error from 16XCLK

—

0

—

%

Note 2, 4

IR113

TX pin rise time and fall

time

—

—

25

ns

Note 2

IR114

16XCLK to TX jitter

—

—

1

↓) to

TXIR rising edge (

7—

8

IR121A

TXIR pulse width

3

—

3

IR121B

1.41

3.5

5

µs

At 9600 baud (Note 5)

IR122

—16

—

IR123

TXIR pin rise time and fall

time

—

—

10

ns

50 pF load (Note 2)

Note 1: Data in the Typical (“Typ”) column is at 5V, +25

°C, unless otherwise stated. These parameters are for

design guidance only and are not tested.

2: These parameters (shaded) are characterized but are not tested. These values should be used for design

guidance only.

3: The TX pin operation may be asynchronous to the 16XCLK pin. This is the error from the desired baud rate

for the system.

4: The TXIR pin operation is synchronous to the 16XCLK pin. Any error present on the 16XCLK pin

(Parameter 1C) will be refelected on the TXIR pin.

5: This specification is not tested. This value is from the design target.

16XCLK

TX

TXIR

01

0

0

0

1

IR100

IR121

Bit

Bit

Bit

Bit

Bit ...

IR122

IR122

IR122

IR122

IR122

IR122

IR114

IR113

IR113

IR115

IR120