AD6645 Datasheet, PDF (1/20 Pages) Analog Devices – 14-Bit, 80 MSPS A/D Converter

a
14-Bit, 80 MSPS
A/D Converter
AD6645
FEATURES
80 MSPS Guaranteed Sample Rate
SNR = 75 dB, f_IN 15 MHz @ 80 MSPS
SNR = 72 dB, f_IN 200 MHz @ 80 MSPS
SFDR = 89 dBc, f_IN 70 MHz @ 80 MSPS
100 dB Multitone SFDR
IF Sampling to 200 MHz
Sampling Jitter 0.1 ps
1.5 W Power Dissipation
Differential Analog Inputs
Pin-Compatible to AD6644
Two’s Complement Digital Output Format
3.3 V CMOS-Compatible
DataReady for Output Latching
APPLICATIONS
Multichannel, Multimode Receivers
Base Station Infrastructure
AMPS, IS-136, CDMA, GSM, WCDMA
Single Channel Digital Receivers
Antenna Array Processing
Communications Instrumentation
Radar, Infrared Imaging
Instrumentation
PRODUCT DESCRIPTION
The AD6645 is a high-speed, high-performance, monolithic
14-bit analog-to-digital converter. All necessary functions,
including track-and-hold (T/H) and reference, are included on
the chip to provide a complete conversion solution. The AD6645
provides CMOS-compatible digital outputs. It is the fourth
generation in a wideband ADC family, preceded by the
AD9042 (12-bit, 41 MSPS), the AD6640 (12-bit, 65 MSPS,
IF sampling), and the AD6644 (14-bit, 40 MSPS/65 MSPS).
Designed for multichannel, multimode receivers, the AD6645 is
part of Analog Device’s SoftCell™ transceiver chipset. The
AD6645 maintains 100 dB multitone, spurious-free dynamic
range (SFDR) through the second Nyquist band. This break-
through performance eases the burden placed on multimode
digital receivers (software radios) that are typically limited by
the ADC. Noise performance is exceptional; typical signal-to-
noise ratio is 74.5 dB through the first Nyquist band.
The AD6645 is built on Analog Devices’ high-speed complemen-
tary bipolar process (XFCB) and uses an innovative, multipass
circuit architecture. Units are available in a thermally enhanced 52-
lead PowerQuad 4^® (LQFP_ED) specified from –40∞C to +85∞C.
PRODUCT HIGHLIGHTS
1. IF Sampling
The AD6645 maintains outstanding ac performance up to
input frequencies of 200 MHz. Suitable for multicarrier 3G
wideband cellular IF sampling receivers.
2. Pin Compatibility
The ADC has the same footprint and pin layout as the
AD6644, 14-Bit 40 MSPS/65 MSPS ADC.
3. SFDR Performance and Oversampling
Multitone SFDR performance of –100 dBc can reduce the
requirements of high-end RF components and allows the use
of receive signal processors such as the AD6620 or AD6624/
AD6624A.
AV_CC
DV_CC
AIN
A1
TH1
AIN
FUNCTIONAL BLOCK DIAGRAM
AD6645
TH2
A2
TH3
TH4
TH5
ADC3
ADC1
DAC1
ADC2
DAC2
6
VREF
2.4V
5
5
ENCODE
ENCODE
INTERNAL
TIMING
DIGITAL ERROR CORRECTION LOGIC
GND
DMID OVR DRY D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
MSB
LSB
SoftCell is a trademark of Analog Devices, Inc.
PowerQuad 4 is a registered trademark of Amkor Technology, Inc.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone]
© Analog Devices, Inc., 2002