Datasheet

AD524
Rev. F | Page 22 of 28
Table 5. Error Budget Analysis
Error Source
AD524C
Specifications Calculation
Effect on
Absolute
Accuracy
at T
A
= 25°C
Effect on
Absolute
Accuracy
at T
A
= 85°C
Effect
on
Resolution
Gain Error ±0.25% ±0.25% = 2500 ppm 2500 ppm 2500 ppm –
Gain Instability 25 ppm (25 ppm/°C)(60°C) = 1500 ppm – 1500 ppm –
Gain Nonlinearity ±0.003% ±0.003% = 30 ppm – – 30 ppm
Input Offset Voltage ±50 μV, RTI ±50 μV/20 mV = ±2500 ppm 2500 ppm 2500 ppm –
Input Offset Voltage Drift
±0.5 μV/°C
–
(±0.5 μV/°C)(60°C) = 30 μV
30 μV/20 mV = 1500 ppm
– 1500 ppm –
Output Offset Voltage
1
±2.0 mV ±2.0 mV/20 mV = 1000 ppm 1000 ppm 1000 ppm –
Output Offset Voltage Drift
1
±25 μV/°C (±25 μV/°C)(60°C)= 1500 μV
1500 μV/20 mV = 750 ppm
– 750 ppm –
Bias Current-Source
Imbalance Error
±15 nA (±15 nA)(100 Ω ) = 1.5 μV
1.5 μV/20 mV = 75 ppm
75 ppm 75 ppm –
Bias Current-Source
Imbalance Drift
±100 pA/°C (±100 pA/°C)(100 Ω )(60°C) = 0.6 μV
0.6 μV/20 mV = 30 ppm
– 30 ppm –
Offset Current-Source
Imbalance Error
±10 nA (±10 nA)(100 Ω ) = 1 μV
1 μV/20 mV = 50 ppm
50 ppm 50 ppm –
Offset Current-Source
Imbalance Drift
±100 pA/°C (100 pA/°C)(100 Ω )(60°C) = 0.6 μV
0.6 μV/20 mV = 30 ppm
– 30 ppm –
Offset Current-Source
Resistance-Error
±10 nA (10 nA)(175 Ω ) = 3.5 μV
3.5 μV/20 mV = 87.5 ppm
87.5 ppm 87.5 ppm –
Offset Current-Source
Resistance-Drift
±100 pA/°C (100 pA/°C)(175 Ω )(60°C) = 1 μV
1 μV/20 mV = 50 ppm
– 50 ppm –
Common Mode Rejection 5 V DC 115 dB 115 dB = 1.8 ppm × 5 V = 8.8 μV
8.8 μV/20 mV = 444 ppm
444 ppm 444 ppm –
Noise, RTI (0.1 Hz to 10 Hz) 0.3 μV p-p 0.3 μV p-p/20 mV = 15 ppm – – 15 ppm
Total Error 6656.5 ppm 10516.5 ppm 45 ppm
1
Output offset voltage and output offset voltage drift are given as RTI figures.