GA1086 Datasheet, PDF (1/12 Pages) TriQuint Semiconductor – 11-Output Clock Buffer

TRIQUINT
S E M I C O N D U C T O R, I N C .
Figure 1. Block Diagram
FBIN S1 CLK S0 NC NC GND
11 10 9
8
7
6
5
S2 12
VDD 13
Q/2 ¹⁴
GND 15
FBOUT 16
Q1 ¹⁷
VDD 18
Control
Logic
Phase
Detector
VCO
Divide
Logic
MUX
Precision
Output
Buffers
4 VDD
3 Q9
2 _Q8
1 GND
28 Q7
27 Q6
26 VDD
19 20 21 22 23
GND Q2 Q3 VDD Q4
24 25
Q5 GND
TriQuint’s GA1086 operates from 30 MHz to 67 MHz. This TTL-level clock
buffer chip supports the tight timing requirements of high-performance
microprocessors, with near zero input-to-output delay and very low pin-to-
pin skew. The device offers 10 usable outputs synchronized in phase and
frequency to a periodic clock input signal. One of the ten outputs is a one-
half clock output (CLK ÷ 2). With split termination, the GA1086 can be
used to drive up to nineteen 15 pF loads, as shown in Figure 10.
The tight control over phase and frequency of the output clocks is achieved
with a 400 MHz internal Phase-Locked Loop (PLL). By feeding back one of
the output clocks to FBIN, the on-chip PLL continuously maintains
synchronization between the input clock (CLK) and all ten outputs. Any
drift or gradual variation in the system clock is matched and tracked at the
ten outputs. The GA1086 output buffers are symmetric, each sourcing and
sinking up to 30 mA of drive current. For diagnostic purposes, the device
has a test mode which is used to test the device and associated logic by
single-stepping through the control logic.
GA1086
11-Output
Clock Buffer
Features
• Operates from 30 MHz to 67MHz
• Pin-to-pin output skew of
250 ps (max)
• Period-to-period jitter:
75 ps (typ)
• Near-zero propagation delay:
–350 ps ± 500 ps or
–350 ps ± 1000 ps
• 10 symmetric, TTL-compatible
outputs with 30 mA drive and
rise and fall times of 1.4 ns(max)
• 28-pin J-lead surface-mount
package
• Special test mode
• Meets or exceeds Pentium^™
processor timing requirements
• Typical applications include
low-skew clock distribution for:
• RISC- or CISC-based systems
• Multi-processor systems
• High-speed backplanes
The GA1086 is fabricated using TriQuint’s One-Up™ gallium arsenide
technology to achieve precise timing control and to guarantee 100% TTL
compatibility. The output frequency makes this device ideal for clock
generation and distribution in a wide range of high-performance
microprocessor-based systems. Many other CISC- and RISC-based
systems will also benefit from its tight control of skew and delay.
For additional information and latest specifications, see our website: www.triquint.com
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