Rainbow Electronics MAX7427 - Manual

General Description
The MAX7426/MAX7427 5th-order, lowpass, elliptic,
switched-capacitor filters (SCFs) operate from a single
+5V (MAX7426) or +3V (MAX7427) supply. The devices
draw only 0.8mA of supply current and allow corner fre-
quencies from 1Hz to 12kHz, making them ideal for
low-power post-DAC filtering and anti-aliasing applica-
tions. They can be put into a low-power mode, reducing
supply current to 0.2µA.
Two clocking options are available: self-clocking (through
the use of an external capacitor) or external clocking for
tighter cutoff-frequency control. An offset-adjust pin
allows for adjustment of the DC output level.
The MAX7426/MAX7427 deliver 37dB of stopband
rejection and a sharp rolloff with a transition ratio of
1.25. Their fixed response limits the design task to
selecting a clock frequency.
Applications
ADC Anti-Aliasing CT2 Base Stations
Post-DAC Filtering Speech Processing
Features
♦ 5th-Order, Elliptic Lowpass Filters
♦ Low Noise and Distortion: -80dB THD + Noise
♦ Clock-Tunable Corner Frequency (1Hz to 12kHz)
♦ Single-Supply Operation
+5V (MAX7426)
+3V (MAX7427)
♦ Low Power
0.8mA (Operating Mode)
0.2µA (Shutdown Mode)
♦ Available in 8-Pin µMAX/PDIP Packages
♦ Low Output Offset: ±4mV
MAX7426/MAX7427
5th-Order, Lowpass, Elliptic,
Switched-Capacitor Filters
________________________________________________________________ Maxim Integrated Products 1
OS
OUT V DD
1
2
8
7
CLK
SHDN IN
GND
COM
µMAX/PDIP
TOP VIEW
3
4
6
5
MAX7426
MAX7427
V DD
IN
CLK
OUT
GND
INPUT
0.1 µF
0.1 µF
CLOCK
SHDN
OUTPUT
COM
OS
MAX7426
MAX7427
V SUPPLY
Typical Operating Circuit
19-1710; Rev 0; 4/00
Pin Configuration
Ordering Information
PART
MAX7426CUA
MAX7426CPA
MAX7426EUA -40°C to +85°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
8 µMAX
8 Plastic DIP
8 µMAX
MAX7426EPA -40°C to +85°C 8 Plastic DIP
PART TRANSITION RATIO
OPERATING
VOLTAGE (V)
MAX7426 r = 1.25 +5
Selector Guide
MAX7427 r = 1.25 +3
MAX7427CUA
MAX7427CPA
MAX7427EUA -40°C to +85°C
0°C to +70°C
0°C to +70°C 8 µMAX
8 Plastic DIP
8 µMAX
MAX7427EPA -40°C to +85°C 8 Plastic DIP
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.