LMH6553SD National Semiconductor, LMH6553SD Datasheet - Page 20

• Manufacturer Part Number: LMH6553SD
• Description: DIFF AMP, 900MHZ, 8LLP, POWERWISE
• Manufacturer: National Semiconductor

Specifications of LMH6553SD

• No. Of Amplifiers: 1
• Gain Db Max: 1dB
• Bandwidth: 900MHz
• Slew Rate: 2300V/µs
• Supply Voltage Range: 4.5V To 12V
• Supply Current: 29.1mA
• Amplifier Case Style: LLP
• No. Of Pins: 8
• Rohs Compliant: Yes

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High Speed Differential Amplifiers to Drive ADCs. For more
information regarding a particular ADC, refer to the particular
ADC datasheet for details.
Product Number
ADC1173
ADC1175
ADC08351
ADC1175-50
ADC08060
ADC08L060
ADC08100
ADC08200
ADC08500
ADC081000
ADC08D1000
ADC10321
ADC10D020
ADC10030
ADC10040
ADC10065
ADC10DL065
ADC10080
ADC11DL066
ADC11L066
ADC11C125
ADC11C170
ADC12010
ADC12020
ADC12040
ADC12D040
ADC12DL040
ADC12DL065
ADC12DL066
ADC12L063
ADC12C080
ADC12DS080
ADC12L080
ADC12C105
ADC12DS105
ADC12C170
ADC14L020
ADC14L040
ADC14C080
ADC14DS080
ADC14C105
ADC14DS105
ADC14155
TABLE 3. DIFFERENTIAL INPUT ADCs COMPATIBLE
WITH LMH6553 DRIVER
Sampling
(MSPS)
Rate
1000
1000
Max
100
200
500
125
170
105
105
170
105
105
155
15
20
42
50
60
60
20
20
27
40
65
65
80
66
66
10
20
40
40
40
65
66
63
80
80
80
20
40
80
80
Resolution
10
10
10
10
10
10
10
11
11
11
11
12
12
12
12
12
12
12
12
12
12
12
12
12
12
14
14
14
14
14
14
14
8
8
8
8
8
8
8
8
8
8
8
Channels
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
DUAL
20
DRIVING CAPACITIVE LOADS
As noted previously, capacitive loads should be isolated from
the amplifier outputs with small valued resistors. This is par-
ticularly the case when the load has a resistive component
that is 500Ω or higher. A typical ADC has capacitive compo-
nents of around 10 pF and the resistive component could be
1000Ω or higher. If driving a transmission line, such as 50Ω
coaxial or 100Ω twisted pair, using matching resistors will be
sufficient to isolate any subsequent capacitance. For other
applications see the Suggested R
charts in the Typical Performance Characteristics section.
BALANCED CABLE DRIVER
With up to 8 V
of linear drive current the LMH6553 makes an excellent cable
driver as shown in Figure 12. The LMH6553 is also suitable
for driving differential cables from a single ended source.
POWER SUPPLY BYPASSING
The LMH6553 requires supply bypassing capacitors as
shown in Figure 13 and Figure 14. The 0.01 µF and 0.1 µF
capacitors should be leadless SMT ceramic capacitors and
should be no more than 3 mm from the supply pins. These
capacitors should be star routed with a dedicated ground re-
turn plane or trace for best harmonic distortion performance.
A small capacitor, ~0.01 µF, placed across the supply rails,
and as close to the chip's supply pins as possible, can further
improve HD2 performance. Narrow traces or small vias will
reduce the effectiveness of bypass capacitors. Also shown in
both figures is a capacitor from the V
ground. These inputs are high impedance and can provide a
coupling path into the amplifier for external noise sources,
possibly resulting in loss of dynamic range, degraded CMRR,
degraded balance and higher distortion.
FIGURE 12. Fully Differential Cable Driver
PP
differential output voltage swing and 100 mA
OUT
CM
vs. Capacitive Load
and V
CLAMP
30043702
pins to