Intel UPI-L42 Driving from AN External Source, LC Oscillator Mode Crystal Oscillator Mode

UPI-C42/UPI-L42

DRIVING FROM AN EXTERNAL SOURCE

NOTE:

See XTAL1 Configuration Table.

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Rise and Fall Times Should Not Exceed 10 ns. Resistors to VCC are Needed to Ensure VIH e 3.5V if TTL Circuitry is Used.

LC OSCILLATOR MODE CRYSTAL OSCILLATOR MODE

L	C	NOMINAL	1
45 H	20 pF	5.2 MHz	f e
				2q0LC˚
120 H	20 pF	3.2 MHz

C˚ e C a 3Cpp 2

Cpp j 5 – 10 pF

Pin-to-Pin Capacitance

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Each C Should be Approximately 20 pF, including Stray Capacitance.

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C1 5 pF (STRAY 5 pF)

C2 (CRYSTAL a STRAY) 8 pF

C3 20 – 30 pF INCLUDING STRAY

Crystal Series Resistance Should be Less Than 30X at 12.5 MHz.

XTAL1 Configuration Table

XTAL1 Connection

1) to Ground	2) 10 KX Resistor	3) Not Connected
	to Ground
Not recommended for CHMOS	Recommended configuration for	Low power configuration
designs. Causes approximately	designs which will use both	recommended for CHMOS only
16 mA of additional current flow	NMOS and CHMOS parts. This	designs to provide lowest
through the XTAL1 pin on UPI-	configuration limits the additional	possible power consumption.
C42 and approximately 11 mA of	current through the XTAL1 pin to	This configuration will not work
additional current through XTAL1	approximately 1 mA, while	with the NMOS device.
on the UPI-L42.	maintaining compatibility with the
	NMOS device.

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