19-1492; Rev 1; 10/01
±5V, 1.5Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
The MAX108 PECL-compatible, 1.5Gsps, 8-bit analog-
to-digital converter (ADC) allows accurate digitizing of
analog signals with bandwidths to 2.2GHz. Fabricated
on Maxim’s proprietary advanced GST-2 bipolar
process, the MAX108 integrates a high-performance
track/hold (T/H) amplifier and a quantizer on a single
The innovative design of the internal T/H, which has an
exceptionally wide 2.2GHz full-power input bandwidth,
results in high performance (typically 7.5 effective bits)
at the Nyquist frequency. A fully differential comparator
design and decoding circuitry reduce out-of-sequence
code errors (thermometer bubbles or sparkle codes)
and provide excellent metastable performance. Unlike
other ADCs that can have errors resulting in false full-
or zero-scale outputs, the MAX108 limits the error mag-
nitude to 1LSB.
The analog input is designed for either differential or
single-ended use with a ±250mV input voltage range.
Dual, differential, positive-referenced emitter-coupled
logic (PECL)-compatible output data paths ensure easy
interfacing and include an 8:16 demultiplexer feature
that reduces output data rates to one-half the sampling
clock rate. The PECL outputs can be operated from any
supply between +3V to +5V for compatibility with +3.3V
or +5V referenced systems. Control inputs are provided
for interleaving additional MAX108 devices to increase
the effective system sampling rate.
The MAX108 is packaged in a 25mm x 25mm, 192-con-
tact Enhanced Super Ball-Grid Array (ESBGA™) and is
specified over the commercial (0°C to +70°C) tempera-
ture range. For pin-compatible, lower speed versions of
the MAX108, see the MAX104 (1Gsps) and the MAX106
(600Msps) data sheets.
Digital RF/IF Signal Processing
Direct RF Downconversion
High-Speed Data Acquisition
o 1.5Gsps Conversion Rate
o 2.2GHz Full-Power Analog Input Bandwidth
o 7.5 Effective Bits at fIN = 750MHz (Nyquist
o ±0.25LSB INL and DNL
o 50Ω Differential Analog Inputs
o ±250mV Input Signal Range
o On-Chip, +2.5V Precision Bandgap Voltage
o Latched, Differential PECL Digital Outputs
o Selectable 8:16 Demultiplexer
o Internal Demux Reset Input with Reset Output
o 192-Contact ESBGA Package
o Pin Compatible with MAX104 (1Gsps) and
0°C to +70°C
Ball Assignment Matrix
Typical Operating Circuit appears at end of data sheet.
ESBGA is a trademark of Amkor/Anam.
PCB land pattern appears at end of data sheet.
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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.