© 2007 Microchip Technology Inc.

DS21618B-page 17

MCP2120

4.3

Timing Diagrams and Specifications

FIGURE 4-3:

External Clock Timing

TABLE 4-3:

EXTERNAL CLOCK TIMING REQUIREMENTS

AC Characteristics

Standard Operating Conditions (unless otherwise specified)

Operating Temperature

–40

Characteristics”

Param.

No.

Sym

Characteristic

Min

Max

Units

Conditions

50

—

—

ns

50

—

500

ns

1A

External CLKIN

DC

—

20

MHz

2—

20

MHz

1C

Clock Error

—

—

0.01

%

3TosL,

TosH

Clock in (OSC1)

Low or High Time

10

—

—

ns

4TosR,

TosF

Clock in (OSC1)

Rise or Fall Time

—

—

15

ns

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: All specified values are based on characterization data for that particular oscillator type under standard

operating conditions with the device executing code. Exceeding these specified limits may result in an

unstable oscillator operation and/or higher than expected current consumption.

When an external clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices.

3: A duty cycle of no more than 60/40 (High Time / Low Time or Low Time / High Time) is recommended for

external clock inputs.

OSC1

Q4

Q1

Q2

Q3

Q4

Q1

13

3

44