參數(shù)資料
型號: AD8370AREZ
廠商: Analog Devices Inc
文件頁數(shù): 7/28頁
文件大?。?/td> 0K
描述: IC AMP VGA DIFF LN 16TSSOP
產(chǎn)品培訓(xùn)模塊: Differential Circuit Design Techniques for Communication Applications
標(biāo)準(zhǔn)包裝: 96
放大器類型: 可變增益
電路數(shù): 1
輸出類型: 差分
轉(zhuǎn)換速率: 5750 V/ns
-3db帶寬: 750MHz
電流 - 輸入偏壓: 400pA
電流 - 電源: 79mA
電壓 - 電源,單路/雙路(±): 3 V ~ 5.5 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 16-TSSOP(0.173",4.40mm)裸露焊盤
供應(yīng)商設(shè)備封裝: 16-TSSOP-EP
包裝: 管件
產(chǎn)品目錄頁面: 775 (CN2011-ZH PDF)
Data Sheet
AD8370
Rev. B | Page 15 of 28
APPLICATIONS
BASIC CONNECTIONS
Figure 44 shows the minimum connections required for basic
operation of the AD8370. Supply voltages between 3.0 V and
5.5 V are allowed. The supply to the VCCO and VCCI pins
should be decoupled with at least one low inductance, surface-
mount ceramic capacitor of 0.1 μF placed as close as possible to
the device.
AD8370
INHI
IC
OM
VCCI
PWUP
VOCM
VCCO
OC
OM
OPH
I
OPLO
OC
OM
VCCO
LTC
H
CL
CK
DAT
A
IC
OM
IN
LO
67
8
23
5
1
11
10
9
15
14
16
13
12
4
SERIAL CONTROL
INTERFACE
100pF
1nF
0.1
F
100pF
0.1
F
+VS (3.0V TO 5.0V)
FERRITE
BEAD
FERRITE
BEAD
1nF
BALANCED
LOAD
RL
BALANCED
SOURCE
RS
2
RS
2
03692-
042
Figure 44. Basic Connections
The AD8370 is designed to be used in differential signal chains.
Differential signaling allows improved even-order harmonic
cancellation and better common-mode immunity than can be
achieved using a single-ended design. To fully exploit these
benefits, it is necessary to drive and load the device in a
balanced manner. This requires some care to ensure that the
common-mode impedance values presented to each set of
inputs and outputs are balanced. Driving the device with an
unbalanced source can degrade the common-mode rejection
ratio. Loading the device with an unbalanced load can cause
degradation to even-order harmonic distortion and premature
output compression. In general, optimum designs are fully
balanced, although the AD8370 still provides impressive
performance when used in an unbalanced environment.
The AD8370 is a fine adjustment, VGA. The gain control
transfer function is linear in voltage gain. On a decibel scale,
this results in the logarithmic transfer functions shown in
Figure 4. At the low end of the gain transfer function, the slope
is steep, providing a rather coarse control function. At the high
end of the gain control range, the decibel step size decreases,
allowing precise gain adjustment.
GAIN CODES
The AD8370’s two gain ranges are referred to as high gain (HG)
and low gain (LG). Within each range, there are 128 possible
gain codes. Therefore, the minimum gain in the low gain range
is given by the nomenclature LG0 whereas the maximum gain
in that range is given by LG127. The same is true for the high
gain range. Both LG0 and HG0 essentially turn off the variable
transconductance stage, and thus no output is available with
these codes (see Figure 26).
The theoretical linear voltage gain can be expressed with respect
to the gain code as
AV = GainCode Vernier (1 + (PreGain 1) MSB)
where:
AV is the linear voltage gain.
GainCode is the digital gain control word minus the MSB
(the final 7 bits).
Vernier = 0.055744 V/V
PreGain = 7.079458 V/V
MSB is the most significant bit of the 8-bit gain control word.
The MSB sets the device in either high gain mode (MSB = 1)
or low gain mode (MSB = 0).
For example, a gain control word of HG45 (or 10101101 binary)
results in a theoretical linear voltage gain of 17.76 V/V,
calculated as
45 × 0.055744 × (1 + (7.079458 1) × 1)
Increments or decrements in gain within either gain range are
simply a matter of operating on the GainCode. Six –dB gain
steps, which are equivalent to doubling or halving the linear
voltage gain, are accomplished by doubling or halving the
GainCode.
When power is first applied to the AD8370, the device is
programmed to code LG0 to avoid overdriving the circuitry
following it.
POWER-UP FEATURE
The power-up feature does not affect the GainCode, and the
gain setting is preserved when in power-down mode. Powering
down the AD8370 (bringing PWUP low while power is still
applied to the device) does not erase or change the GainCode
from the AD8370, and the same gain code is in place when the
device is powered up, that is, when PWUP is brought high
again. Removing power from the device all together and
reapplying, however, reprograms to LG0.
相關(guān)PDF資料
PDF描述
LT1352IS8#PBF IC OP AMP DUAL HI SPD 3MHZ 8SOIC
AD8625ARUZ IC OPAMP JFET 5MHZ QUAD 14TSSOP
4-103327-0-26 CONN HEADR BRKWAY .100 26POS STR
AD8625ARZ IC OPAMP JFET 5MHZ QUAD 14SOIC
AD8024ARZ IC OPAMP CF QUAD LP 50MA 16SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD8370AREZ 制造商:Analog Devices 功能描述:IC VARIABLE GAIN AMP 750MHZ TSSOP-16 制造商:Analog Devices 功能描述:IC, VARIABLE GAIN AMP, 750MHZ, TSSOP-16
AD8370AREZ1 制造商:AD 制造商全稱:Analog Devices 功能描述:LF to 750 MHz, Digitally Controlled VGA
AD8370AREZ-RL7 功能描述:IC AMP VGA DIFF LN 16TSSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:150 系列:- 放大器類型:音頻 電路數(shù):2 輸出類型:- 轉(zhuǎn)換速率:5 V/µs 增益帶寬積:12MHz -3db帶寬:- 電流 - 輸入偏壓:100nA 電壓 - 輸入偏移:500µV 電流 - 電源:6mA 電流 - 輸出 / 通道:50mA 電壓 - 電源,單路/雙路(±):4 V ~ 32 V,±2 V ~ 16 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:8-TSSOP 包裝:管件
AD8370-EVAL 制造商:Analog Devices 功能描述:AD8370 EVAL BOARD - Bulk
AD8370-EVALZ 制造商:Analog Devices 功能描述:- Bulk