MAX1448EVKIT Maxim Integrated Products, MAX1448EVKIT Datasheet - Page 14

• Manufacturer Part Number: MAX1448EVKIT
• Description: EVAL KIT FOR MAX1448
• Manufacturer: Maxim Integrated Products

Specifications of MAX1448EVKIT

• Number Of Adc's: 1
• Number Of Bits: 10
• Sampling Rate (per Second): 80M
• Data Interface: Parallel
• Inputs Per Adc: 1 Differential
• Input Range: ±1 V
• Power (typ) @ Conditions: 120mW @ 80MSPS
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Utilized Ic / Part: MAX1448
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 6 shows the relationship between the clock
input, analog input, and data output. The MAX1448
samples at the falling edge of the input clock. Output
data is valid on the rising edge of the input clock. The
output data has an internal latency of 5.5 clock cycles.
Figure 6 also shows the relationship between the input
clock parameters and the valid output data.
Figure 7 shows a typical application circuit containing a
single-ended to differential converter. The internal refer-
ence provides a V
purposes. The input is buffered and then split to a volt-
age follower and inverter. A lowpass filter follows the op
amps to suppress some of the wideband noise associ-
ated with high-speed op amps. The user may select the
R
to suit a particular application. For the application in
Figure 7, an RISO of 50Ω is placed before the capaci-
tive load to prevent ringing and oscillation. The 22pF
C
10-Bit, 80Msps, Single 3.0V, Low-Power
ADC with Internal Reference
Figure 6. System and Output Timing Diagram
14
ISO
IN
ANALOG INPUT
CLOCK INPUT
DATA OUTPUT
capacitor acts as a small bypassing capacitor.
______________________________________________________________________________________
and C
IN
values to optimize the filter performance
Applications Information
System Timing Requirements
DD
t
/2 output voltage for level shifting
D0
N - 6
N
N - 5
N + 1
N - 4
N + 2
5.5 CLOCK-CYCLE LATENCY
t
CH
N - 3
An RF transformer (Figure 8) provides an excellent
solution for converting a single-ended source signal to
a fully differential signal, required by the MAX1448 for
optimum performance. Connecting the transformer’s
center tap to COM provides a V
the input. Although a 1:1 transformer is shown, a step-
up transformer may be selected to reduce the drive
requirements. A reduced signal swing from the input
driver, such as an op amp, may also improve the over-
all distortion.
In general, the MAX1448 provides better SFDR and
THD with fully differential input signals than single-
ended drive, especially for very high input frequencies.
In differential input mode, even-order harmonics are
lower since both inputs (IN+, IN-) are balanced, and
each of the inputs only requires half the signal swing
compared to single-ended mode.
Figure 9 shows an AC-coupled, single-ended applica-
tion. The MAX4108 op amp provides high speed, high
bandwidth, low noise, and low distortion to maintain the
integrity of the input signal.
N + 3
Single-Ended AC-Coupled Input Signal
N - 2
N + 4
t
CL
Using Transformer Coupling
N - 1
N + 5
DD
N
N + 6
/2 DC level shift to
N + 1