Datasheet

© 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°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
(1)
Max Units Conditions
1TOSC External CLKIN Period
(2,3)
50 — — ns
Oscillator Period
(2)
50 — 500 ns
1A F
OSC External CLKIN
Frequency
(2,3)
DC — 20 MHz
Oscillator Frequency
(2)
2—20MHz
1C E
CLK 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
133
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