SBOSA28B August   2023  – August 2026 LOG200

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 High Speed, Logarithmic Current-to-Voltage Conversion
      2. 6.3.2 Voltage and Current References
      3. 6.3.3 Adaptive Photodiode Bias
      4. 6.3.4 Auxiliary Operational Amplifier
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Logarithmic Transfer Function
        1. 7.1.1.1 Logarithmic Conformity Error
        2. 7.1.1.2 Error Analysis Example
    2. 7.2 Typical Application
      1. 7.2.1 Optical Current Sensing
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5.5 Electrical Characteristics

at TA = 25°C, VS = 5V (±2.5V) to 10V (±5V), OUTA RL = 10kΩ connected to VS / 2, OUTB RL = 2kΩ connected to VS / 2,
VCM = VREFA = VS / 2, VREFGND = VS–, II1 = 1µA, and II2 = 1µA (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
LOG CONFORMITY ERROR
Logarithmic conformity error II1 = 10nA to 100µA 0.004 0.017 dB
0.05 ±0.2 %
TA = 0°C to 85°C 0.004 0.026 dB
0.05 ±0.3 %
II1 = 10nA to 1mA  0.007 0.044 dB
0.08 ±0.5 %
TA = 0°C to 85°C 0.007 0.087 dB
0.08 ±1 %
II1 = 1nA to 10mA 0.022 0.065 dB
0.25 ±0.75 %
TA = 0°C to 85°C 0.022 0.131 dB
0.25 ±1.5 %
TA = –40°C to +125°C,
VS = 5V (1)		 0.030 0.265 dB
0.35 ±3 %
TA = –40°C to +125°C,
VS = 10V (1)		 0.044 0.265 dB
0.5 ±3 %
TRANSFER FUNCTION (GAIN)
Initial scaling factor II1 = 100pA to 10mA 250 mV/decade
Scaling factor error II1 = 1nA to 100µA LOG200RGT –1 0.15 1 %
LOG200YBH –1.5 1.5
TA = 0°C to 85°C LOG200RGT –1.1 1.1
LOG200YBH –1.5 1.5
II1 = 100pA to 10mA 0.4
TA = 0°C to 85°C, VS = 5V 0.5
TA = 0°C to 85°C, VS = 10V 0.7
TA = –40°C to +125°C, VS = 5V (1) 3.8
TA = –40°C to +125°C, VS = 10V (1) 6.3
LOGARITHMIC AMPLIFIER INPUT
VOS Offset voltage VI1 – VCM II1 = 10nA, VS = 5V LOG200RGT –3 –0.84 3 mV
II1 = 10nA, VS = 5V LOG200YBH –5 –0.84 4.5
II1 = 10nA, VS = 10V LOG200RGT –4 –1.6 2
II1 = 10nA, VS = 10V LOG200YBH –5.75 –1 3.75
II1 = 100µA 32 50
II1 = 100µA, 
TA = –40°C to +125°C		 42
VI2 – VCM II2 = 10nA, VS = 5V –3 –0.89 3
II2 = 10nA, VS = 10V –4 –1.4 2
II2 = 100µA, VS = 5V –0.66 3
II2 = 100µA, VS = 10V –1.2 2
II2 = 100µA, 
TA = –40°C to +125°C		   –1.5
dVOS/dT VI1 – VCM 22 µV/°C
VI2 – VCM –7
VCM Input common mode voltage (VS–) + 2.3 (VS+) – 2.0 V
IBIAS ratio VIBIAS = (VS+) – 1.0V,
VS = 5V		 II1 = 100µA 1.069 1.127 1.185 A/A
VIBIAS = (VS+) – 1.0V,
VS = 5V		 II1 = 10mA LOG200RGT 1.094 1.128 1.161
LOG200YBH 1.058 1.128 1.176
VIBIAS = (VS+) – 1.0V,
VS = 10V		 II1 = 100µA 1.069 1.127 1.184
VIBIAS = (VS+) – 1.0V,
VS = 10V		 II1 = 10mA LOG200RGT 1.128 1.162 1.195
LOG200YBH 1.109 1.162 1.209
LOGARITHMIC AMPLIFIER OUTPUT
VOSO Output offset voltage 1.3 ±7.5 mV
TA = –40°C to +125°C 2.5 ±10 mV
PSRR Power supply rejection ratio II1 = II2 = 1µA ±0.1 mV/V
CMRR Common-mode rejection ratio (2) (VS–) + 2.3V < VCM < (VS+) – 2.0V, II1 = II2 = 1µA 60 dB
Voltage output swing (VS–) + 0.3 (VS+) – 0.3 V
Short-circuit current ±20 mA
Capacitive load 100 pF
AUXILIARY OPERATIONAL AMPLIFIER
Offset voltage 46 ±700 µV
TA = –40°C to +125°C   0.07 ±1 mV
Offset voltage drift 0.53 ±3 µV/°C
Input bias current   –0.84 ±3 µA
TA = –40°C to +125°C   –1.2
Input offset current 18 ±100 nA
TA = –40°C to +125°C 45 ±300
Input common mode voltage (VS–) + 1.0 (VS+) – 1.0 V
Input voltage noise density f = 0.1Hz to 10kHz 50 nVRMS
f = 1kHz   4.1   nV/√Hz
Input current noise f = 1kHz   1.2   pA/√Hz
AOL Open-loop voltage gain (VS–) + 200mV < VO < (VS+) – 200mV, RL = 10kΩ LOG200RGT 126 150 dB
LOG200YBH 124 150
TA = –40°C to +125°C 126
(VS–) + 200mV < VO < (VS+) – 200mV, RL = 2kΩ 124 140
TA = –40°C to +125°C 124
PSRR Power supply rejection ratio –1 µV/V
CMRR Common-mode rejection ratio (VS–) + 1.0 < VCM < (VS+) – 1.0 130 dB
GBW Gain-bandwidth product CL = 28pF 60 MHz
Unity-gain bandwidth 42 MHz
SR Slew rate 2V step, G = 1 22 V/μs
tS Settling time To 0.1%, 2V step, G = 1 Rising 110 ns
Falling 400
To 0.01%, 2V step, G = 1 Rising 550
Falling 1100
CIN Input capacitance Differential 2.6 pF
Common-mode 0.7
ZO Open-loop output impedance f = 1MHz 7.5 Ω
CURRENT REFERENCE
IIREF IREF initial current 0.98 1 1.02 µA
IREF initial accuracy –2 0.3 2 %
Temperature coefficient 35 ppm/℃
VIREF IREF compliance voltage (VS–) (VS+) – 1.0 V
Output impedance ΔVIREF / ΔIIREF 3 GΩ
VOLTAGE REFERENCE
VREF165 REF165 initial voltage 1.645 1.65 1.655 V
REF165 initial accuracy –0.3 0.06 0.3 %
VREF25 REF25 initial voltage 2.494 2.5 2.506 V
REF25 initial accuracy –0.24 0.05 0.24 %
Temperature coefficient REF165 reference, REF25 reference 20 ppm/℃
Load regulation REF165 reference, –2mA < IREF165 < 5mA –360 µV/mA
REF25 reference, –2mA < IREF25 < 5mA –475
Line regulation 5V < VS < 10V REF165 reference 16 µV/V
REF25 reference 30
Short-circuit current –14 mA
Noise 4.2 µVRMS
NOISE
Voltage noise (2) (3) f = 1kHz, II2 = IREF II1 = 1nA 2000 nV/√Hz
II1 = 10nA 650
II1 = 100nA 210
II1 = 1µA 110
FREQUENCY RESPONSE
BW –3dB bandwidth (4) (3) I1 input II2 = IREF, II1 = 100pA 12 kHz
II2 = IREF, II1 = 1nA 90
II2 = IREF, II1 = 10nA 0.5 MHz
II2 = IREF, II1 = 100nA 2.3
II2 = IREF, II1 = 1µA 6.3
II2 = IREF, II1 = 10µA to 10mA 20
I2 input II1 = IREF, II2 = 100pA 0.05 kHz
II1 = IREF, II2 = 1nA 0.5
II1 = IREF, II2 = 10nA 5.2
II1 = IREF, II2 = 100nA 55
II1 = IREF, II2 = 1µA 0.55 MHz
II1 = IREF, II2 = 10µA to 10mA 6 MHz
Step response, I1 (5) (3) II2 = IREF,
II1 = 100pA to 1nA		 Rising 9 µs
Falling 30
II2 = IREF,
II1 = 1nA to 10nA		 Rising 1.2
Falling 5
II2 = IREF,
II1 = 10nA to 100nA		 Rising 0.24
Falling 0.62
II2 = IREF,
II1 = 100nA to 1µA		 Rising 0.06
Falling 0.15
II2 = IREF,
II1 = 100µA to 1mA		 Rising 0.02
Falling 0.03
POWER SUPPLY
IQ Quiescent current IOUTA = IOUTB = 0mA 9.5 10 mA
TA = –40°C to +125°C 13
(1) The result of this calculation is dominated by the error from TA = 95°C to 125°C.
(2) Output referred.
(3) Measurement parasitic CIN of 3pF nominal.
(4) Assumes parasitic CIN of 3pF or less.
(5) Step response is defined as 10% to 90%.