Refer to the PDF data sheet for device specific package drawings
The LOG200 is a wide-dynamic-range current-to-voltage amplifier specifically designed to optimize current measurements across 160dB of dynamic range with unparalleled accuracy and speed for optical communications, medical diagnostics, and industrial process-control measurements. The LOG200 features two logarithmic amplifiers followed by a high-accuracy differential amplifier that convert current signals into a voltage representing the log-compressed ratio of the two currents. The current inputs are designed to feature a high-speed response from one input, and a highly accurate reference signal on the other input, allowing for a unique combination of fast transient response and high logarithmic conformity.
The LOG200 ratio is internally set to 250mV/decade of current-to-voltage conversion. The device integrates an uncommitted high-speed amplifier to allow the output to be configured for differential or filtered responses, with a fast settling time to drive successive approximation analog-to-digital converters (SAR ADCs). The LOG200 also features a separate reference current and reference voltage designed to configure the device for optimized input current and common-mode voltages.
The LOG200 can be powered in a single-supply (4.5V to 12.6V) or dual-supply (±2.25V to ±6.3V) configuration and is specified from –40°C to +125°C.
PART NUMBER | PACKAGE(1) | PACKAGE SIZE(2) |
---|---|---|
LOG200 | RGT (VQFN, 16) | 3mm × 3mm |
YBH (DSBGA, 16)(3) | 1.6mm × 1.6mm |
PIN | TYPE | DESCRIPTION | ||
---|---|---|---|---|
NAME | NO. | |||
RGT (VQFN) | YBH (DSBGA) | |||
+IN | 14 | B4 | Input | Auxiliary op-amp voltage non-inverting input |
–IN | 13 | A4 | Input | Auxiliary op-amp voltage inverting input |
I1 | 1 | D4 | Input | Current input for logarithm numerator |
I2 | 3 | D2 | Input | Current input for logarithm denominator |
IBIAS | 15 | C4 | Output | Photodiode adaptive biasing current output |
IREF | 4 | D1 | Output | Reference current output |
REFA | 10 | B3 | Input | Logarithmic difference amplifier reference input |
OUTA | 11 | A2 | Output | Logarithmic difference amplifier output |
OUTB | 12 | A3 | Output | Auxiliary op-amp voltage output |
REF165 | 9 | B2 | Output | 1.65V voltage reference output |
REF25 | 5 | C2 | Output | 2.5V voltage reference output |
REFGND | 6 | C1 | Power | Voltage reference negative potential |
VCM | 2 | D3 | Input | Input common-mode voltage |
VCM2 | 16 | C3 | Input | Input common-mode voltage. Connect to VCM. |
VS+ | 8 | A1 | Power | Positive supply voltage |
VS– | 7 | B1 | Power | Negative supply voltage |
Thermal Pad | PAD | N/A | — | Thermal Pad. Connect to VCM to minimize leakage on I1 pin. |