ADA4622-2ACPZ-R7 datasheet(30/38 Pages) AD

30 / 38 page

ADA4622-1/ADA4622-2/ADA4622-4

Data Sheet

Rev. E | Page 30 of 38

APPLICATIONS INFORMATION

RECOMMENDED POWER SOLUTION

The ADA4622-1/ADA4622-2/ADA4622-4 can operate from a

±2.5 V to ±15 V dual supply or a 5 V to 30 V single supply. The

ADP7118 and the ADP7182 are recommended to generate the

clean positive and negative rails for the ADA4622-1/ADA4622-2/

ADA4622-4. Both low dropout (LDO) regulators are available in

fixed output voltage or adjustable output voltage versions. To

generate the input voltages for the LDOs, the ADP5070 dc-to-dc

switching regulator is recommended. Figure 91 shows the

recommended power solution configuration for the ADA4622-1/

ADA4622-2/ADA4622-4.

ADP5070

ADP7118

ADP7182

+12V

+16V

+15V

–15V

–16V

Figure 91. Power Solution Configuration for the

ADA4622-1/ADA4622-2/ADA4622-4

Table 12. Recommended Power Management Devices

Product

Description

ADP5070

DC-to-DC switching regulator with independent

positive and negative outputs

ADP7118

20 V, 200 mA, low noise, CMOS LDO regulator

ADP7182

−28 V, −200 mA, low noise, linear regulator

MAXIMUM POWER DISSIPATION

The maximum power the ADA4622-1/ADA4622-2/ADA4622-4

can safely dissipate is limited by the associated rise in junction

temperature. For plastic packages, the maximum safe junction

temperature is 150°C. If this maximum temperature is exceeded,

reduce the die temperature to restore proper circuit operation.

Leaving the device in the overheated condition for an extended

period of time can result in device burnout. To ensure proper

operation, it is important to observe the specifications shown in

the Absolute Maximum Ratings and Thermal Resistance sections.

SECOND-ORDER LOW-PASS FILTER

Figure 92 shows the ADA4622-1/ADA4622-2/ADA4622-4

configured as a second-order, Butterworth, low-pass filter. With

the values as shown, the corner frequency equals 200 kHz. The

following equations show the component selection:

R1 = R2 = User Selected (Typical Values: 10 kΩ to 100 kΩ)

CUTOFF ×

2π

1.414

CUTOFF ×

2π

0.707

ADA4622-1/

ADA4622-2/

ADA4622-4

0.1µF

+5V

0.1µF

VOUT

VIN

28pF

–5V

56pF

20k

Ω

20k

Ω

50pF

Figure 92. Second-Order, Butterworth, Low-Pass Filter

Figure 93 shows a plot of the filter; greater than 35 dB of high

frequency rejection is achieved.

100

–50

–40

–30

–20

–10

10k

100k

FREQUENCY (Hz)

10M

100M

Figure 93. Frequency Response of the Filter

WIDEBAND PHOTODIODE PREAMPLIFIER

The ADA4622-1/ADA4622-2/ADA4622-4 are an excellent

choice for photodiode preamplifier applications. The low input

bias current minimizes the dc error at the output of the pre-

amplifier. In addition, the high gain bandwidth product and low

input capacitance maximizes the signal bandwidth of the

photodiode preamplifier. Figure 94 shows the ADA4622-1/

ADA4622-2/ADA4622-4 as a current to voltage (I to V)

converter with an electrical model of a photodiode.

–

VOUT

RSH = 1011Ω

IPHOTO

ADA4622-1/

ADA4622-2/

ADA4622-4

Figure 94. Wideband Photodiode Preamplifier

ADA4622-2ACPZ-R7 数据表(PDF) 30 Page - Analog Devices

ADA4622-2ACPZ-R7 数据表(HTML) 30 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

数据表下载