SBAU473 EVM User's guide

SBAU473A January 2025 – February 2025 AMC1200 , AMC1200-Q1 , AMC1202 , AMC1300 , AMC1300B-Q1 , AMC1301 , AMC1301-Q1 , AMC1302 , AMC1302-Q1 , AMC1400 , AMC1400-Q1 , AMC21C12 , AMC22C11 , AMC22C11-Q1 , AMC22C12 , AMC22C12-Q1 , AMC23C10 , AMC23C11 , AMC23C12 , AMC23C12-Q1 , AMC23C14 , AMC23C15 , AMC23C15-Q1 , AMC3301 , AMC3301-Q1 , AMC3302 , AMC3302-Q1

4.1.3 Full Signal Chain Evaluation Procedure

Note: Verify that the outputs of the connected supplies are disabled before connecting or disconnecting equipment.

Set the 5V (±10%) source and limit the current to 50mA as noted above. Connect the EVM voltage source to the VDD pin of the connector, referenced to GND2. Turn on the power source and verify that there is no more than the specified current limit in the device data sheet drawn.
Connect DMMs to the following test points. Refer to Figure 4-1, Figure 4-2, and Figure 2-1 for test procedure setup and connection mapping.
1. High Current Power Supply Control Shunt: $V_{IN}$
2. AMC3302 Input, INP & INN: $V_{INP / INN}$
3. AMC3302 Differential Output, OUTP & OUTN: $V_{OUT_DIFF}$
4. AMC3302 Single-Ended Output, OUT(SE) & GND: $V_{OUT_SE}$
5. AMC23C15 Output, OUT1 (or OUT2) & GND: $V_{OUT 1}$
Connect the high current carrying cables to the positive and negative lugs, IN+ and IN-. For high-side measurement of positive current, IN– sources to the electronic load; for negative current, IN+ sources to the load. Set current bounds if supplies allow. Turn on all connected supplies.
Apply the appropriate full-scale linear input sweep ±50A range (or ±70A). Incrementing 0.5A every 0.2s works well for evaluation.
Record the five DMM outputs for the entire full-scale linear input sweep.
To evaluate the current sensing performance of the EVM, calculate the following errors across the entire current sweep. Equations "i" calculate the error at a given input current and equations "ii" calculate the error over a specified current range at a given input current. Example range is ±50A.
1. Default Values:
  $. R_{IND} = 4.9 kΩ$
  $. I_{B} = 36 μA$
  $. {GAIN}_{AMC 3302} = 41$
  $. V_{OFFSET} = 2.5 V$
  Shunt Resistor Error:
  $. i . E_{SHUNT} = V_{IN} \times \frac{R_{IND}}{R_{IND} + R_{5} + R_{8}} + I_{B} \times R_{18} - V_{INP / INN}$
  $. ii . E_{SHUNT % FS} = \frac{E_{SHUNT}}{E_{SHUNT} (I_{I N} = - 50 A) - E_{SHUNT} (I_{I N} = 50 A)} \times 100$
2. AMC3302 Error:
  $. i . E_{AMC 3302} = V_{OUT_DIFF} - V_{INP / INN} \times \frac{R_{IND}}{R_{IND} + R_{5} + R_{8}} \times {GAIN}_{AMC 3302}$
  $. ii . E_{AMC 3302 % FS} = \frac{E_{AMC 3302}}{E_{AMC 3302} (I_{I N} = - 50 A) - E_{AMC 3302} (I_{I N} = 50 A)} \times 100$
3. Differential to Single-Ended Error:
  $. i . E_{DIFF \to SE} = V_{OUT_SE} - V_{OUT_DIFF} \times \frac{R_{4}}{R_{7}} + V_{OFFSET}$
  $. ii . E_{DIFF \to SE % FS} = \frac{E_{DIFF \to SE}}{E_{DIFF \to SE} (I_{I N} = - 50 A) - E_{DIFF \to SE} (I_{I N} = 50 A)} \times 100$
4. Total Error:
  $. i . E_{TOTAL} = V_{OUT_SE} - V_{OFFSET} + (V_{IN} \times \frac{R_{IND}}{R_{IND} + R_{5} + R_{8}} + I_{B} \times R_{18}) \times {GAIN}_{AMC 3302} \times \frac{R_{4}}{R_{7}}$
  $. ii . E_{TOTAL % FS} = \frac{E_{TOTAL}}{E_{TOTAL} (I_{I N} = - 50 A) - E_{TOTAL} (I_{I N} = 50 A)} \times 100$
Plot calculated results against input current, I_IN. Results shown taken over temperature from two samples.
Figure 4-3 AMC-AMP-50A-EVM Total Error %FS Results
To evaluate the overcurrent detection performance, measure V_OUT1 or V_OUT2. By default, V_OUT1 is low at I_IN = ±72A or V_IN = ±72mV ± 2.5mV and V_OUT2 toggles at V_IN =±60mV.
Repeat these steps at hot and cold temps. Calibrate if necessary.