Datasheet AD8304 (Analog Devices) - 4

AD8304–Typical Performance Characteristics (VP = 5 V, VN = 0 V, TA = 25 C, unless otherwise noted.) 1.6 0.510 TA = –40 C, +25 C, +85 C TA = –40 C, +25 C, +85 C V 1.4 N = –0.5V 0.508 1.2 –40 C 0 C 1.0 +25 C +70 C 0.506 V +85 C V – – 0.8 LOG SUM V V 0.504 –40 C 0.6 +25 C 0.4 +85 C 0.502 0.2 0 0.500 100p 1n 10n 100n 1 10 100 1m 10m 100p 1n 10n 100n 1 10 100 1m 10m INPUT – A INPUT – A
TPC 1. VLOG vs. IPD TPC 4. VSUM vs. IPD
2.0 2.8 TA = –40 C, +25 C, +85 C TA = –40 C, +25 C, +85 C 2.6 1.5 VN = –0.5V 2.4 1.0 –40 C –40 C 2.2 +25 C +85 C 0.5 0 +25 C C 2.0 V – 1.8 0 PDB 1.6 V OR – dB (10mV/dB) –0.5 1.4 +85 C ERR +70 C 1.2 –1.0 1.0 –1.5 0.8 –2.0 0.6 100p 1n 10n 100n 1 10 100 1m 10m 0 1 2 3 4 5 6 7 8 9 10 INPUT – A INPUT – mA
TPC 2. Logarithmic Conformance (Linearity) for VLOG TPC 5. VPDB vs. IPD
2.0 2.4 1.25 VP = 4.5V, 5.0V, 5.5V TA = –40 C, +25 C, +85 C 1.5 VN = –0.1V 2.2 V 1.00 P = 3.0V 0.75 1.0 2.0 1.8 –40 C 0.50 0.5 4.5V V 1.6 0.25 – 0 5.0V OUT +25 C 5.5V V 1.4 0 –0.5 +85 C OR – dB (10mV/dB) 1.2 –0.25 OM IDEAL OUTPUT – dB (10mV/dB) ERR –1.0 1.0 –0.50 OR FR –1.5 0.8 –0.75 ERR –2.0 0.6 –1.00 100p 1n 10n 100n 1 10 100 1m 10m 100p 1n 10n 100n 1 10 100 1m 10m INPUT – A INPUT – A
TPC 3. Absolute Deviation from Nominal Speci- TPC 6. Logarithmic Conformance (Linearity) for a fied Value of VLOG for Several Supply Voltages 3 V Single Supply (See Figure 6) –4– REV. A Document Outline FEATURES APPLICATIONS PRODUCT DESCRIPTION FUNCTIONAL BLOCK DIAGRAM SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION PIN FUNCTION DESCRIPTIONS ORDERING GUIDE Typical Performance Characteristics BASIC CONCEPTS Optical Measurements Decibel Scaling GENERAL STRUCTURE Bandwidth and Noise Considerations Chip Enable USING THE AD8304 Slope and Intercept Adjustments Low Supply Slope and Intercept Adjustment Using the Adaptive Bias Changing the Voltage at the Summing Node Implementing Low-Pass Filters Operation in Comparator Modes Using a Negative Supply APPLICATIONS Summing Node at Ground and Voltage Inputs Providing Negative Outputs and Rescaling Inverting the Slope Programmable Level Comparator with Hysteresis Programmable Multidecade Current Source Characterization Setups and Methods Evaluation Board OUTLINE DIMENSIONS Revision History