ICS1562A
Integrated
Circuit
Systems, Inc.
User Programmable Differential Output Graphics Clock Generator
Description
Features
The ICS1562A is a very high performance monolithic phaselocked loop (PLL) frequency synthesizer. Utilizing ICS’s advanced CMOS mixed-mode technology, the ICS1562A
provides a low cost solution for high-end video clock generation.
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The ICS1562A has differential video clock outputs (CLK+ and
CLK-) that are compatible with industry standard video DAC.
Another clock output, LOAD, is provided whose frequency is
derived from the main clock by a programmable divider. An
additional clock output is available, LD/N2, which is derived
from the LOAD frequency and whose modulus may also be
programmed.
Operating frequencies are fully programmable with direct control provided for reference divider, prescaler, feedback divider
and post-scaler.
Reset of the pipeline delay on Brooktree RAMDAC s may
be performed under register control. Outputs may also be set
to desired states to facilitate circuit board testing.
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Two programming options:
ICS1562A-001 (Parallel Programming)
ICS1562A-201 (Serial Programming)
Supports high-resolution graphics - CLK output to
260 MHz, with 400 MHz options available
Eliminates need for multiple ECL output crystal oscillators
Fully programmable synthesizer capability - not just a
clock multiplier
Circuitry included for reset of Brooktree RAMDAC pipeline delay
VRAM shift clock generation capability
(-201 option only)
Line-locked clock generation capability
External feedback loop capability (-201 option only)
Compact - 16-pin 0.150” skinny SOIC package
Fully backward compatible to ICS1562
ICS1562A - 001 Pinout
Simplified Block Diagram - ICS1562A
LOOP
FILTER
XTAL1
BLANK
EXTFBK
PHASEFREQUENCY
DETECTOR
MUX
/A
/M
14
AD3
4
13
VDD
5
12
VDDO
6
11
IPRG
LOAD
(-201 only)
3
VSS
PRESCALER
AD2
XTAL2
VCO
AD1
STROBE
CHARGE
PUMP
16
15
7
10
CLK+
LD/N2
/R
1
2
VSS
CRYSTAL
OSCILLATOR
XTAL2
AD0
XTAL1
8
9
CLK-
FEEDBACK DIVIDER
PROGRAMMING
INTERFACE
16-Pin SOIC
MUX
/2
DIFF.
OUTPUT
CLK+
CLK−
/4
ICS1562A - 201 Pinout
EXTFBK
/ N1
MUX
DRIVER
LOAD
1
16
DATA
XTAL1
2
15
HOLD
BLANK
XTAL2
/ N2
DRIVER
LD/N2
3
14
DATCLK
4
13
VDD
VSS
5
12
VDDO
VSS
Figure 1
RAMDAC is a trademark of Brooktree Corporation.
ICS1562ARevB091294
6
11
IPRG
LOAD
7
10
CLK+
LD/N2
8
9
CLK-
16-Pin SOIC
