OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

MK2761ASLFTR

P1-P3P4-P6P7-P7
DATASHEET
SET-TOP CLOCK SOURCE MK2761A
IDT™
SET-TOP CLOCK SOURCE 1
MK2761A REV F 051310
Description
The MK2761A is a low-cost, low-jitter, high-performance
clock synthesizer for set-top box applications. Using analog
Phase-Locked Loop (PLL) techniques, the device accepts a
27 MHz crystal or clock input to produce multiple output
clocks including the processor clock, the UART clock, a
selectable audio clock, and four low skew copies of the 27
MHz. The audio clocks are frequency-locked to the 27 MHz
using our patented zero ppm error techniques. This allows
audio and video to track exactly, thereby eliminating the
need for large buffer memory.
IDT manufactures a large variety of Set-top Box and
multimedia clock synthesizers for all applications. Consult
IDT to eliminate crystals and oscillators from your board.
Features
• Packaged in a 16-pin narrow (150 mil) SOIC
• Pb (lead) free package
• Selectable audio sampling frequencies support 32, 44.1,
and 48 kHz in most DACs
• 27 MHz crystal or clock input
• Processor frequency of 16.67 MHz
• Fixed clocks of 27 and 3.6864 MHz
• Zero ppm in audio clocks exactly track video frequency
• 25 mA output drive capability at TTL levels
• Advanced, low-power, sub-micron CMOS process
• Operating voltage of 5.0 V ±10%
Block Diagram
27.000 MHz
Crystal
Ocsillator
ACS1:0
3.6864 MHz
VDD
GND
Clock
Synthesis and
Control
Circuitry
2
3
16.667 MHz
Audio Clock
X1
X2
27.000 MHz
crystal or clock
2
4
MK2761A
SET-TOP CLOCK SOURCE CLOCK SYNTHESIZER
IDT™
SET-TOP CLOCK SOURCE 2
MK2761A REV F 051310
Pin Assignment
Audio Clock (MHz) DecodingTable
Pin Descriptions
1
2
3
GND
4
X2
5
6
27 MHz
7
8
27 MHz
VDD
27 MHz3.68 MHz
ACS0
16.67 MHz
GND
X1/ICLK
16
ACS1
VDD
ACLK
27 MHz
GND
15
14
13
12
11
10
9
16-pin (150 mil) SOIC
ACS1 ACS0 ACLK
0 0 8.192
0 1 11.2896
1 0 12.288
1 1 5.6448
Pin
Number
Pin
Name
Pin
Type
Pin Description
1 ACS1 Input Audio clock Select 1. Selects ACLK on pin 8. See table above.
2 X2 XO Crystal connection. Connect to 27 MHz crystal. Leave unconnected for clock
input.
3 X1/ICLK XI Crystal connection. Connect to 27 MHz crystal or to a 27 MHz input clock.
4 VDD Power Connect to +5 V.
5 GND Power Connect to ground.
6 16.67M Output 16.667 MHz processor clock output.
7 3.68M Output 3.6864 MHz clock output.
8 ACLK Output Audio clock output. Determined by status of ACS1, ACS0. See table above
9 GND Power Connect to ground.
10 27M Output 27 MHz buffered reference clock output. Duty cycle matches input clock.
11 27M Output 27 MHz buffered reference clock output. Duty cycle matches input clock.
12 GND Power Connect to ground.
13 VDD Power Connect to +5 V.
14 27M Output 27 MHz buffered reference clock output. Duty cycle matches input clock.
15 27M Output 27 MHz buffered reference clock output. Duty cycle matches input clock.
16 ACS0 Input Audio clock Select 0. Selects audio clock on pin 8. See table above.
MK2761A
SET-TOP CLOCK SOURCE CLOCK SYNTHESIZER
IDT™
SET-TOP CLOCK SOURCE 3
MK2761A REV F 051310
External Components
The MK2761A requires a minimum number of external components for proper operation. Decoupling capacitors of
0.1µF should be connected between VDD and GND, as close to the MK2761A as possible. A series termination
resistor of 33Ω may be used for each clock output. If a clock input is not used, the 27 MHz crystal must be
connected as close to the chip as possible. The crystal should be a fundamental mode (do not use third overtone),
parallel resonant, 50 ppm or better. Crystal capacitors should be connected from pins X1 to ground and X2 to
ground. The value of these capacitors is given by the following equation, where CL is the crystal load capacitance:
Crystal caps (pF) = (CL-4) x 2. So, for a crystal with 16 pF load capacitance, the crystal caps should be 24 pF each.
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the MK2761A. These ratings, which are
standard values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these
or any other conditions above those indicated in the operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical
parameters are guaranteed only over the recommended operating temperature range.
Recommended Operation Conditions
Item Rating
Supply Voltage, VDD 7 V
All Inputs and Outputs -0.5 V to VDD+0.5 V
Ambient Operating Temperature 0 to +70° C
Storage Temperature -65 to +150° C
Junction Temperature 125° C
Soldering Temperature 260° C
Parameter Min. Typ. Max. Units
Ambient Operating Temperature 0 +70 ° C
Power Supply Voltage (measured in respect to GND) +4.5 +5.5 V
P1-P3P4-P6P7-P7

MK2761ASLFTR

Mfr. #:
Buy MK2761ASLFTR
Manufacturer:
IDT
Description:
Clock Synthesizer / Jitter Cleaner SET TOP CLOCK SOURCE
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet