ACPL-C799 Datasheet, PDF (10/16 Pages) Broadcom Corporation. – Optically Isolated ±50 mV Sigma-Delta Modulator

ACPL-C799
Data Sheet
Definitions
Figure 11 I_DD2 (V_DD2 = 5V) vs. V_IN DC Input at Various
Temperatures
8
7
105°C
25°C
6
-40°C
5
4
3
2
1
-100 -75 -50 -25 0 25 50 75 100
V_IN (mV)
Figure 12 Clock Frequency vs. Temperature for Various V_DD1
12
11
10
9
8
-50 -25
5.5V
5.0V
4.5V
0 25 50 75 100
Temperature (°C)
Definitions
Integral Nonlinearity (INL)
INL is the maximum deviation of a transfer curve from a
straight line passing through the endpoints of the ADC transfer
function, with offset and gain errors adjusted out.
Differential Nonlinearity (DNL)
DNL is the deviation of an actual code width from the ideal
value of 1 LSB between any two adjacent codes in the ADC
transfer curve. DNL is a critical specification in closed-loop
applications. A DNL error of less than ±1 LSB guarantees no
missing codes and a monotonic transfer function.
Offset Error
Offset error is the deviation of the actual input voltage
corresponding to the mid-scale code (32,768 for a 16-bit
system with an unsigned decimation filter) from 0 V. Offset
error can be corrected by software or hardware.
Gain Error (Full-Scale Error)
Gain error includes positive full-scale gain error and negative
full-scale gain error. Positive full-scale gain error is the
deviation of the actual input voltage corresponding to positive
full-scale code (65,535 for a 16-bit system) from the ideal
differential input voltage (V_IN+ – V_IN- = +80 mV), with offset
error adjusted out. Negative full-scale gain error is the
deviation of the actual input voltage corresponding to
negative full-scale code (0 for a 16-bit system) from the ideal
differential input voltage (V_IN+ – V_IN- = -80 mV), with offset
error adjusted out. Gain error includes reference error. Gain
error can be corrected by software or hardware.
Signal-to-Noise Ratio (SNR)
The SNR is the measured ratio of AC signal power to noise
power below half of the sampling frequency. The noise power
excludes harmonic signals and DC.
Signal-to-(Noise + Distortion) Ratio (SNDR)
The SNDR is the measured ratio of AC signal power to noise
plus distortion power at the output of the ADC. The signal
power is the rms amplitude of the fundamental input signal.
Noise plus distortion power is the rms sum of all
non-fundamental signals up to half the sampling frequency
(excluding DC).
Effective Number of Bits (ENOB)
The ENOB determines the effective resolution of an ADC,
expressed in bits, defined by
ENOB = (SNDR – 1.76) / 6.02
Isolation Transient Immunity (CMR)
The isolation transient immunity (also known as
Common-Mode Rejection or CMR) specifies the minimum
rate-of-rise/fall of a common-mode signal applied across the
isolation boundary beyond which the modulator clock or data
is corrupted.
Broadcom
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