19-3077; Rev 1; 2/04
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
General Description
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.
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.
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.
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.
For pin-compatible, higher resolution versions of the
MAX1121, refer to the MAX1122 (170Msps), the
MAX1123 (210Msps), and the MAX1124 (250Msps)
data sheets.
♦
250Msps Conversion Rate
♦
SNR = 48.8dB/48.7dB at f
IN
= 100MHz/500MHz
♦
SFDR = 68dBc/63.8dBc at f
IN
= 100MHz/500MHz
♦
Single 1.8V Supply
♦
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)
Features
MAX1121
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
68 QFN-EP*
MAX1121EGK
-40°C to +85°C
*EP
= Exposed paddle.
Pin Configuration
TOP VIEW
OGND
AGND
AGND
AGND
AV
CC
OV
CC
AV
CC
AV
CC
ORN
D7N
D6N
ORP
D5N
51
D4P
50
D4N
49
D3P
48
D3N
47
D2P
46
D2N
45
OGND
44
OV
CC
43
DCLKP
42
DCLKN
41
OV
CC
40
D1P
39
D1N
38
D0P
37
D0N
36
N.C.
35
N.C.
D7P
D6P
N.C.
68
67 66 65 64
63 62 61 60 59 58
57 56 55 54 53 52
Applications
Wireless and Wired Broadband Communication
Digital Oscilloscopes
Digital Predistortion Receivers
Communications Test Equipment
Radar and Satellite Subsystems Antenna Array
Processing
Instrumentation
AV
CC
AGND
REFIO
REFADJ
AGND
AV
CC
AGND
INP
INN
1
2
3
4
5
6
7
8
9
EP
MAX1121
AGND
10
AV
CC
11
AV
CC
12
AV
CC
13
AV
CC
14
AGND
15
AGND
16
CLKDIV
17
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
AGND
AV
CC
CLKP
CLKN
N.C.
N.C.
N.C.
D5P
T/B
OGND
AGND
AGND
AGND
OV
CC
________________________________________________________________
Maxim Integrated Products
OV
CC
AV
CC
N.C.
N.C.
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
