120 dB Range (3 nA to 3 mA)
Dual Logarithmic Converter
ADL5310
FUNCTIONAL BLOCK DIAGRAM
FEATURES
2 independent channels optimized for photodiode
665kΩ
VREF
VRDZ
OUT1
VSUM
IRF1
interfacing
6-decade input dynamic range
V
OUT1
COMM
Law conformance 0.3 dB from 3 nA to 3 mA
Temperature-stable logarithmic outputs
Nominal slope 10 mV/dB (200 mV/dec), externally scalable
Intercepts may be independently set by external resistors
User-configurable output buffer amplifiers
Single- or dual-supply operation
SCL1
BIN1
V
BIAS
6.69kΩ
I
LOG
TEMPERATURE
COMPENSATION
VNEG
LOG1
451Ω
14.2kΩ
Space-efficient, 24-lead 4 mm × 4 mm LFCSP
Low power: < 10 mA quiescent current
I
INP1
IRF2
PD1
OUT2
REFERENCE
GENERATOR
0.5V
2.5V
V
OUT2
20kΩ
COMM
80kΩ
APPLICATIONS
Gain and absorbance measurements
Multichannel power monitoring
General-purpose baseband log compression
SCL2
BIN2
V
BIAS
14.2kΩ
I
LOG
TEMPERATURE
VNEG
COMPENSATION
LOG2
451Ω
PRODUCT DESCRIPTION
6.69kΩ
The ADL53101 low cost, dual logarithmic amplifier converts
input current over a wide dynamic range to a linear-in-dB
output voltage. It is optimized to determine the optical power
in wide-ranging optical communication system applications,
including control circuitry for lasers, optical switches, atten-
uators, and amplifiers, as well as system monitoring. The device
is equivalent to a dual AD8305 with enhanced dynamic range
(120 dB). While the ADL5310 contains two independent signal
channels with individually configurable transfer function
constants (slope and intercept), internal bias circuitry is shared
between channels for improved power consumption and
channel matching. Dual converters in a single, compact LFCSP
package yield space-efficient solutions for measuring gain or
attenuation across optical elements. Only a single supply is
required; optional dual-supply operation offers added flexibility.
INP2
I
PD2
COMM
VSUM
665kΩ
VREF
Figure 1.
The logarithmic slope is set to 10 mV/dB (200 mV/decade)
nominal and can be modified using external resistors and the
independent buffer amplifiers. The logarithmic intercepts for
each channel are defined by the individual reference currents,
which are set to 3 μA nominal for maximum input range by
connecting ±±5 kΩ resistors between the 2.5 V VREF pins and
the IRF1 and IRF2 inputs. Tying VRDZ to VREF effectively sets
the x-intercept four decades below the reference current—
typically 300 pA for a 3 µA reference.
The ADL5310 employs an optimized translinear structure that
use the accurate logarithmic relationship between a bipolar
transistor’s base emitter voltage and collector current, with
appropriate scaling by precision currents to compensate for the
inherent temperature dependence. Input and reference current
pins sink current ranging from 3 nA to 3 mA (limited to ±±0 dB
between input and reference) into a fixed voltage defined by the
VSUM potential. The VSUM potential is internally set to
500 mV but may be externally grounded for dual-supply opera-
tion, and for additional applications requiring voltage inputs.
The use of individually optimized reference currents may
be valuable when using the ADL5310 for gain or absorbance
measurements where each channel input has a different current-
range requirement. The reference current inputs
are also fully functional dynamic inputs, allowing log ratio
operation with the reference input current as the denominator.
The ADL5310 is specified for operation from –40°C to +85°C.
1 US Patents: 4,604,532, 5,519,308. Other patents pending.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.326.8703
www.analog.com
© 2004 Analog Devices, Inc. All rights reserved.
5秒后页面跳转
MAX6675资料手册参数详解、引脚配置说明
LM258引脚图及功能介绍、主要参数分析
CD4052资料手册参数详解、引脚配置说明
一文带你了解TPS5430资料手册分析：参数介绍、引脚配置说明
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
