MAX104 Maxim, MAX104 Datasheet - Page 25

• Manufacturer Part Number: MAX104
• Description: 5V / 1Gsps / 8-Bit ADC with On-Chip 2.2GHz Track/Hold Amplifier
• Manufacturer: Maxim

Table 7. Thermal Performance for
MAX104 With or Without Heatsink
The MAX104 has been modeled to determine the ther-
mal resistance from junction to ambient. Table 7 lists
the ADC’s thermal performance parameters:
Ambient Temperature:
Heatsink Dimensions:
PC Board Size and Layout:
Aavid Engineering and IERC provide open-tool, low-
profile heatsinks, fitting the 25mm x 25mm ESBGA
package.
Aavid Engineering, Inc.
Phone: [phone]
Heatsink Catalog #: 335224B00032
Heatsink Dimensions: 25mm x 25mm x 10mm
International Electronic Research Corporation (IERC)
Phone: [phone]
Heatsink Catalog #: BDN09-3CB/A01
Heatsink Dimensions: 23.1mm x 23.1mm x 9mm
Grounding and power-supply decoupling strongly influ-
ence the MAX104’s performance. At 1GHz clock fre-
quency and 8-bit resolution, unwanted digital crosstalk
may couple through the input, reference, power supply,
and ground connections and adversely influence the
dynamic performance of the ADC. Therefore, closely
follow the grounding and power-supply decoupling
guidelines (Figure 22).
(linear ft./min.)
AIRFLOW
200
400
800
0
Bypassing/Layout/Power Supply
______________________________________________________________________________________
HEATSINK
WITHOUT
16.5
14.3
12.5
13
On-Chip 2.2GHz Track/Hold Amplifier
MAX104
Heatsink Manufacturers
T
25mm x 25mm x 10mm
4" x 4"
2 Signal Layers
2 Power Layers
A
Thermal Performance
= +70°C
JA
WITH HEATSINK
(°C/W)
12.5
9.4
8.3
7.4
±5V, 1Gsps, 8-Bit ADC with
Maxim strongly recommends using a multilayer printed
circuit board (PCB) with separate ground and power-
supply planes. Since the MAX104 has separate analog
and digital ground connections (GNDA, GNDI, GNDR,
and GNDD, respectively), the PCB should feature sep-
arate analog and digital ground sections connected at
only one point (star ground at the power supply). Digital
signals should run above the digital ground plane, and
analog signals should run above the analog ground
plane. Keep digital signals far away from the sensitive
analog inputs, reference inputs, and clock inputs. High-
speed signals, including clocks, analog inputs, and
digital outputs, should be routed on 50Ω microstrip
lines, such as those employed on the MAX104EVKIT.
The MAX104 has separate analog and digital power-
supply inputs: V
and V
bution, bandgap reference, and reference amplifier;
V
V
based circuit sections; and V
logic circuits of the data converter.
The MAX104 V
open while the part is being powered up. To avoid this
condition, add a high-speed Schottky diode (such as a
Motorola 1N5817) between V
prevents the device substrate from forward biasing,
which could cause latchup.
Figure 21. MAX104 Thermal Performance
CC
CC
O (+3V to V
A (+5V) to supply the ADC’s comparator array;
CC
I (+5V) to power the T/H amplifier, clock distri-
18
16
14
12
10
8
6
0
THERMAL RESISTANCE vs. AIRFLOW
100
EE
CC
EE
200
D) to establish power for all PECL-
supply contacts must not be left
(-5V analog and substrate supply)
AIRFLOW (linear ft./min.)
300 400 500 600 700 800
WITH HEATSINK
EE
CC
and GNDI. This diode
D (+5V) to supply all
WITHOUT
HEATSINK
25