2.13.1 Current Monitor
(Ask a Question)Unless otherwise noted, current monitor performance is specified at 25 °C with nominal power supply voltages, with the output measured using the internal voltage reference with the internal ADC in 12-bit mode and 91 Ksps, after digital compensation. All results are based on averaging over 16 samples.
| Specification | Test Conditions | Min. | Typical | Max. | Units |
|---|---|---|---|---|---|
| Input voltage range (for driving ADC over full range) | 0–48 | 0–50 | 1–51 | mV | |
| Analog gain | From the differential voltage across the input pads to the ADC input | — | 50 | — | V/V |
| Input referred offset voltage | Input referred offset voltage | 0 | 0.1 | 0.5 | mV |
| –55ºC to +125ºC | 0 | 0.1 | 0.5 | mV | |
| Gain error | Slope of BFSL vs. 50V/V | — | ±0.1 | ±0.7 | % nom. |
| –55ºC to +125ºC | — | — | ±0.7 | % nom. | |
| Overall Accuracy | Peak error from ideal transfer function, 25 °C | — | ±(0.1 +0.25%) | ±(0.4 +1.5%) | mV plus % reading |
| –55ºC to +125ºC | — | ±(0.1 +0.25%) | ±(1.5 +1.5%) | mV plus % reading | |
| Input referred noise | 0 VDC input (no output averaging) | 0.3 | 0.4 | 0.5 | mVrms |
| Common-mode rejection ratio | 0V to 12VDC common-mode voltage | –86 | –87 | — | dB |
| Analog settling time | To 0.1% of final value (with ADC load) | ||||
| From CM_STB (High) | 5 | — | — | µs | |
| From ADC_START (High) | 5 | — | 200 | µs | |
| Input capacitance | — | 8 | — | pF | |
| Input biased current | CM[n] or TM[n] pad, –40 °C to +100 °C over maximum input voltage range (plus is into pad) | — | — | — | |
| Strobe = 0; IBIAS on CM[n] | — | 0 | — | µA | |
| Strobe = 1; IBIAS on CM[n] | — | 1 | — | µA | |
| Strobe = 0; IBIAS on TM[n] | — | 2 | — | µA | |
| Strobe = 1; IBIAS on TM[n] | — | 1 | — | µA | |
| Power supply rejection ratio | DC (0–10 KHz) | 41 | 42 | — | dB |
| Incremental operational current monitor power supply current requirements (per current monitor instance, not including ADC or VAREFx) | VCC33A | — | 150 | — | µA |
| VCC33AP | — | 140 | — | µA | |
| VCC15A | — | 50 | — | µA | |
Note: Under no condition should the TM pad ever be greater than 10 mV above the CM pad. This restriction is applicable only if current monitor is used.