MAX9315
Detailed Description
The MAX9315 is a low-skew, 1-to-5 differential driver
designed for clock or data distribution. A 2-to-1 MUX
selects one of the two differential clock inputs, CLK0,
CLK0 or CLK1, CLK1. The MUX is switched by the sin-
gle-ended SEL input. A logic low selects the CLK0,
CLK0 input and a logic high selects the CLK1, CLK1
input. The SEL logic threshold is set by the internal volt-
age reference VBB. SEL can be driven to VCC and VEE
or by a single-ended LVPECL/LVECL signal. The
selected input is reproduced at five differential outputs.
Synchronous Enable
The MAX9315 is synchronously enabled and disabled
with outputs in the low state to eliminate shortened
clock pulses. EN is connected to the input of an edge-
triggered D flip-flop. After power-up, drive EN low and
toggle the selected clock input to enable the outputs.
The outputs are enabled on the falling edge of the
selected clock input after EN goes low. The outputs are
set to a low state on the falling edge of the selected
clock input after EN goes high. The threshold for EN is
equal to VBB.
Supply
For interfacing to differential HSTL and LVPECL signals,
the VCC range is from +2.375V to +3.8V (with VEE
grounded), allowing high-performance clock or data
distribution in systems with a nominal +2.5V or +3.3V
supply. For interfacing to differential LVECL, the VEE
range is -2.375V to -3.8V (with VCC grounded). Output
levels are referenced to VCC and are considered
LVPECL or LVECL, depending on the level of the VCC
supply. With VCC connected to a positive supply and
1:5 Differential LVPECL/LVECL/HSTL
Clock and Data Driver
6
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Pin Description
PIN
NAME
FUNCTION
1
Q0
Noninverting Q0 Output. Typically terminate with 50
resistor to VCC - 2V.
2
Q0
Inverting Q0 Output. Typically terminate with 50
resistor to VCC - 2V.
3
Q1
Noninverting Q1 Output. Typically terminate with 50
resistor to VCC - 2V.
4
Q1
Inverting Q1 Output. Typically terminate with 50
resistor to VCC - 2V.
5
Q2
Noninverting Q2 Output. Typically terminate with 50
resistor to VCC - 2V.
6
Q2
Inverting Q2 Output. Typically terminate with 50
resistor to VCC - 2V.
7
Q3
Noninverting Q3 Output. Typically terminate with 50
resistor to VCC - 2V.
8
Q3
Inverting Q3 Output. Typically terminate with 50
resistor to VCC - 2V.
9
Q4
Noninverting Q4 Output. Typically terminate with 50
resistor to VCC - 2V.
10
Q4
Inverting Q4 Output. Typically terminate with 50
resistor to VCC - 2V.
11
VEE
Negative Supply Voltage
12
SEL
Clock Select Input (Single Ended). Drive low to select the CLK0, CLK0 input. Drive high to select the
CLK1, CLK1 input. The SEL threshold is equal to VBB.
13
CLK0
Noninverting Differential Clock Input 0. Internal 75k
pulldown to VEE.
14
CLK0
Inverting Differential Clock Input 0. Internal 75k
pullup to VCC and 75k pulldown to VEE.
15
VBB
Reference Output Voltage. Connect to the inverting or noninverting clock input to provide a
reference for single-ended operation. When used, bypass with a 0.01F ceramic capacitor to VCC;
otherwise, leave open.
16
CLK1
Noninverting Differential Clock Input 1. Internal 75k
pulldown to VEE.
17
CLK1
Inverting Differential Clock Input 1. Internal 75k
pullup to VCC and 75k pulldown to VEE.
18, 20
VCC
Positive Supply Voltage. Bypass VCC to VEE with 0.1F and 0.01F ceramic capacitors. Place the
capacitors as close to the device as possible with the smaller value capacitor closest to the device.
19
EN
Output Enable Input. Outputs are synchronously enabled on the falling edge of the selected clock
input when EN is low. Outputs are synchronously driven low on the falling edge of the selected
clock input when EN is high.