19-3077; Rev 1; 2/04
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
General Description
Features
The MAX1121 is a monolithic 8-bit, 250Msps analog-to-
digital converter (ADC) optimized for outstanding
dynamic performance at high IF frequencies up to
500MHz. The product operates with conversion rates of
up to 250Msps while consuming only 477mW.
♦ 250Msps Conversion Rate
♦ SNR = 48.8dB/48.7dB at f = 100MHz/500MHz
IN
♦ SFDR = 68dBc/63.8dBc at f = 100MHz/500MHz
♦ Single 1.8V Supply
IN
At 250Msps and an input frequency of 100MHz, the
MAX1121 achieves a spurious-free dynamic range
(SFDR) of 68dBc. Its excellent signal-to-noise ratio
(SNR) of 48.9dB at 10MHz remains flat (within 0.5dB)
for input tones up to 500MHz. This makes the MAX1121
ideal for wideband applications such as digital predis-
tortion in cellular base-station transceiver systems.
♦ 477mW Power Dissipation at 250Msps
♦ On-Chip Track-and-Hold and Internal Reference
♦ On-Chip Selectable Divide-by-2 Clock Input
♦ LVDS Digital Outputs with Data Clock Output
♦ Evaluation Kit Available (Order MAX1124EVKIT)
The MAX1121 requires a single 1.8V supply. The ana-
log input is designed for either differential or single-
ended operation and can be AC- or DC-coupled. The
ADC also features a selectable on-chip divide-by-2
clock circuit, which allows the user to apply clock fre-
quencies as high as 500MHz. This helps to reduce the
phase noise of the input clock source. A differential
LVDS sampling clock is recommended for best perfor-
mance. The converter’s digital outputs are LVDS com-
patible, and the data format can be selected to be
either two’s complement or offset binary.
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX1121EGK
-40°C to +85°C
68 QFN-EP*
*EP = Exposed paddle.
The MAX1121 is available in a 68-pin QFN with
exposed paddle (EP) and is specified over the industri-
al (-40°C to +85°C) temperature range.
Pin Configuration
For pin-compatible, higher resolution versions of the
MAX1121, refer to the MAX1122 (170Msps), the
MAX1123 (210Msps), and the MAX1124 (250Msps)
data sheets.
TOP VIEW
68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52
Applications
Wireless and Wired Broadband Communication
AV
1
2
3
4
5
6
7
8
9
51 D4P
50 D4N
49 D3P
48 D3N
47 D2P
46 D2N
45 OGND
CC
EP
AGND
REFIO
Digital Oscilloscopes
REFADJ
AGND
Digital Predistortion Receivers
Communications Test Equipment
AV
CC
AGND
INP
44 OV
CC
Radar and Satellite Subsystems Antenna Array
Processing
INN
43 DCLKP
42 DCLKN
MAX1121
AGND 10
AV
AV
AV
AV
11
12
13
14
41 OV
CC
CC
CC
CC
CC
Instrumentation
40 D1P
39 D1N
38 D0P
37 D0N
36 N.C.
35 N.C.
AGND 15
AGND 16
CLKDIV 17
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.