MCP2122

DS21894B-page 24

Preliminary

 2004 Microchip Technology Inc.

FIGURE 4-8:

RXIR AND RX WAVEFORMS

TABLE 4-8:

RXIR 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

RXIR Error

—

—

± 2

%

Note 2, 3

Host UART RX Error

—

0

—

%

Note 2, 4

RX pin rise time and fall

time

——

25

ns

Receive (RX pin) Bit Rate

16

—

16

edge (

↓ or ↑) to RX falling

edge (

↓)

—4

—

—3

—

RXIR pulse width

1.41

—

µs

—16

—

16XCLK to RXIR jitter

—

—

1

16XCLK to RX skew

—

—

2.5

µs

RXIR Filter

0.7

—

1.4

µs

Note 5

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 RXIR pin operation is asynchronous to the 16XCLK pin. This is the error from the desired baud rate for

the system.

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

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

5: The minimum specification ensures that ALL pulses less then this pulse width are rejected, the maximum

specification ensures that ALL pulses greater than this pulse width are never rejected, and pulse widths

between these may or may not be rejected.

16XCLK

RX

RXIR

01

0

0

0

1

IR131A

IR110

IR132

IR132

IR132

IR132

IR132

IR132

Bit

Bit

Bit

Bit

Bit ...

IR133

IR134

Note: Refer to Figure 4-2 for load conditions.

IR103

IR103

IR132

IR132

IR132

IR132

IR132

IR132

IR130