ACPL-C797T Datasheet, PDF (1/15 Pages) AVAGO TECHNOLOGIES LIMITED – Automotive Optically Isolated Sigma-Delta Modulator

ACPL-C797T
Automotive Optically Isolated Sigma-Delta Modulator
Data Sheet
Description
The ACPL-C797T is a 1-bit, second-order sigma-delta (Σ-∆)
modulator that converts an analog input signal into a
high-speed data stream with galvanic isolation based on
optical coupling technology. The ACPL-C797T operates
from a 5 V power supply with dynamic range of 79 dB with
an appropriate digital filter. The differential inputs of ±200
mV (full scale ±320 mV) are ideal for direct connection to
shunt resistors or other low-level signal sources in applica-
tions such as motor phase current measurement.
The ACPL-C797T isolated modulator converts a low-
bandwidth analog input into a high-speed one-bit data
stream by means of a Sigma-Delta (Σ-∆) over-sampling
modulator. The modulator data and on-chip sampling
clock are encoded and transmitted across the isolation
boundary where they are recovered and decoded into
separate high-speed clock and data channels. Combined
with superior optical coupling technology, the modulator
delivers high noise margins and excellent immunity
against isolation-mode transients.
Offered in a a compact SSO-8 package, the isolated
ADC delivers the reliability, small size, superior isolation
and over-temperature performance that motor drive
designers need to accurately measure current. Avago
R²Coupler^TM isolation products provide the reinforced in-
sulation and reliability needed for critical automotive and
high-temperature industrial applications.
Functional Block Diagram
V_DD1 1
8 ^VDD2
VIN+ ₂
LED
DRIVER
7 MCLK
Features
• Qualified to AEC-Q100 Grade 1 Test Guidelines
• Automotive temperature range: -40 °C to +125 °C
• 1-bit, second-order sigma-delta modulator
• 10 MHz internal clock
• 16-bit resolution no missing codes (12 bits ENOB)
• Signal-to-Noise Ratio: 79 dB Typ.
• Gain error: ±1%
• ±200 mV linear range with single 5 V supply (±320 mV
full scale)
• Wide supply range for digital interface: 3 V to 5.5 V
• Compact, surface mount SSO-8 package
• Superior optical isolation and insulation
• Common-mode transient immunity: 25 kV/µs
• Safety and regulatory approval:
– IEC/EN/DIN EN 60747-5-5: 1414 V_PEAK working insu-
lation voltage
– UL 1577: 5000 V_RMS/1 minute isolation voltage
– CSA: Component Acceptance Notice #5
Applications
• Automotive electric motor phase and rail current
sensing
• Automotive inverter DC bus current sensing
• Automotive battery current sensing
• Automotive DC-DC converter current sensing
• Automotive AC-DC Charger current sensing
• General-purpose current and voltage sensing
V_{IN- 3}
BUF VREF
6 ^MDAT
GND1 ₄ ^CLOCK
5 ^GND2
Figure 1.
CAUTION: It is advised that normal static precautions be taken in handling and assembly
of this component to prevent damage and/or degradation which may be induced by ESD.