The SFP200MOD is a shunt-based, automotive-rated precision module that can measure currents ranging from mA to 1500 A continuously. The module uses SFP200 IC and Sendyne SFP 18 μΩ shunt to achieve an accuracy of ±1.0% (usually ±0.5%) across -40 °C to 125 °C.
The module monitors bidirectional DC current across the shunt and three high-voltage channels (800 V nominal, 1000 V / channel max). It also provides charge, discharge, and total Coulomb outputs. The module is entirely isolated and can be attached to a battery's high and low sides.
A nominal +5 V or +5 V to +53 V voltage supply rail can power the module. The module automatically adjusts for the shunt's temperature-dependent resistance variation. Every part of the module, excluding the connectors, complies with AEC-Q100. A 500 kbit/s isolated CAN 2.0B interface is used for communications. The SFP200 IC reference design is implemented in this module.
Highlights
Superior Accuracy
- A patented dynamic self-calibration algorithm ensures accurate SOC and EV range calculations with an accuracy of ±0.5%
- Helps get rid of mistakes over time
Reduced Power Losses and Lower Self-Heating
- Ultra-low resistance for reduced system losses and easier thermal control
- Thermal losses from an 18 µΩ shunt resistor are 28% less than those from a 25 µΩ shunt and 64% less than those from a 50 µΩ shunt
Simple, Cost-Effective Integration
- Calibrated and compensated, ready for use
- Production calibration is not required
Flexible Configuration
- People can customize the feature set.
Applications
Image Credit: Sensata Technologies BV
Features
- Reaches an accuracy of more than ±1.0% (usually ±0.5%) for current measurement
- Three high-voltage potentials are measured: 800 V nominal, 1000 V maximum per channel
- Uses an isolated CAN2.0B interface to communicate (500 kbits/s)
- Measures currents between mA and 1500 A
- Uses Sendyne's patented zero offset functionality
- Automatically adjusts for the shunt's fluctuating resistance to temperature (Gain Error)
- Isolated front end for "high" or "low" side current sensing and attenuation of system-induced noise
- Automotive temperature range: -40 °C to 125 °C
- Low power consumption
- Integrated calibration for voltage readings
- Separate charge, discharge, and total Coulomb counters
- All components, save connections, are AEC-Q100 compliant
- Implementation of the SFP200 IC reference design
SFP200MOD Technical Specifications
Operating Specifications
Image Credit: Sensata Technologies BV
Source: Sensata Technologies BV
| Parameters |
Value |
| Shunt value |
18 μOhm |
| Power supply |
Power supply accepts input of anywhere from +5 V to +53 V |
| Interface |
CAN 2.0B isolated,120 Ω terminated |
| Current measurement range |
±600 A continuous / ±1500 A (70 s) when attached to 108 mm2 busbars, <±1.0 % error |
| Rating |
Automotive |
| Power consumption |
< 300 mW at +5 V power supply |
Electrical Specifications
Image Credit: Sensata Technologies BV
Source: Sensata Technologies BV
| Parameter |
Min |
Typical |
Max |
Units |
Conditions / Comments |
| Power and General |
| Shunt & electronics operating temperature range |
-40 |
|
125 |
°C |
|
| Operating temperature range for connectors |
-40 |
|
105 |
°C |
|
| Supply Voltage |
4.5 |
5 |
5.5 |
V |
|
| 5 |
|
53 |
V |
|
| Supply Current |
|
|
50 |
mA |
|
| Start-up time |
|
0.5 |
0.75 |
s |
After initial application of power and power supply stabilization |
| Current Measurement |
| Total Shunt Resistance |
16 |
18 |
20 |
μΩ |
|
| Nominal Full-scale current |
|
±600 |
|
A |
Continuous rating in still air at room temperature of 23 °C with module connected to 108 mm2 busbars on each side |
| Peak Full-scale current |
±1514 |
±1717 |
|
A |
Maximum current value that is measured without clipping; less than 220 s duration, the same conditions as above |
| Current offset error* |
-50 |
<±20 |
+50 |
mA |
Uncalibrated performance applies over the full operating temperature range |
| Current noise error* |
|
<25 |
50 |
mARMS |
1 Hz reporting rate |
| Current value error* |
-0.25 |
|
+0.25 |
% |
Room temperature, test current ±20 A or higher |
| |
-0.5 |
|
+0.5 |
% |
0 °C to +50 °C, test current as above |
| -1 |
|
+1 |
% |
-40 °C to +125 °C, test current as above |
| |
±1 |
|
% |
End of life, test current as above |
| Current measurement resolution |
|
<100 |
|
μA |
Minimum discernible current change; corresponds to one count of Analog to Digital Converter (ADC), 1 Hz current report rate |
| Charge measurement resolution |
|
<1 |
|
μC |
Minimum discernible amount of charge change, 100 Hz report rate |
| Voltage Measurement |
| Nominal Full-scale voltage range |
|
±800 |
|
V |
In reference to negative terminal of the shunt |
| Maximum transient voltage |
±982 |
±1002 |
|
V |
Maximum voltage value measured and reported without clipping or distortion |
| Voltage offset error |
-300 |
<±50 |
+300 |
mV |
VX = 0 V, applies over the full ambient operating temperature range, TA = -40 °C to 125 °C |
| Voltage gain error |
|
<±1 |
|
% |
Over full operating temperature range, TA = -40 °C to +125 °C |
| Voltage noise error |
|
<12 |
30 |
mVRMS |
1 Hz reporting rate |
| Voltage measurement resolution |
|
<1 |
|
mV |
Minimum discernible voltage change; corresponds to one count of ADC, voltage report rate of 10 Hz or lower |
| Impedance of the voltage measurement inputs |
|
12 |
|
MΩ |
Resistive dividers utilized for the voltage inputs consist of four (4) elements connected in-series. Combined Limiting Element Voltage is 2 kV, and combined Maximum Overload Voltage is 4 kV |
| Temperature Measurement (For shunt temperature measurement) |
| Absolute temperature measurement error |
-5 |
±0.5 |
+5 |
°C |
Built-in temperature sensor for shunt temperature measurements |
| Temperature measurement resolution |
|
|
10 |
m°C |
Practical temperature measurement granularity |
| Isolation |
| Test voltage |
|
3 |
|
kVDC |
CAN interface to shunt, 1 min duration |
* The combined Total Current Error is the ±sum of Current offset error, Current noise error, and [Current value error] x [measured value]. For currents over 100 A the Current offset error and the Current noise error could be omitted from the calculation since they will typically contribute less than 0.05 % to the error.
Image Credit: Sensata Technologies BV
Communication
Source: Sensata Technologies BV
| Interface |
Spec |
Speed |
Termination |
Number of units in the same CAN branch |
| CAN |
2.0B |
500 kbits/s |
120 Ω |
16 (only one unit with CAN termination) |
CAN Addresses Selection
The module supports up to 16 distinct CAN addresses, allowing several modules to use a single CAN bus stub. When many devices are connected to the same CAN branch, only one device may have a 120 Ω termination between the two CAN communication lines (assuming the Host has the termination at the other end).
The termination resistor is already put in the modules; if more than one device is connected to the CAN bus, the termination resistor must be removed from all but one module. This resistor (R39) is situated on the other side, next to the PCB's edge, and close to connector P1's center pins. This 0603-sized resistor can be easily cut off with tiny diagonal cutters or unsoldered and reinstalled if needed.
One or more of the four switches on the quad-switch unit must be activated to select a particular set of addresses. For the new settings to take effect, the module must be powered off (supply voltage withdrawn) for ten seconds after the switches have been adjusted. In other words, any modifications performed while the device is powered on will not be considered until the subsequent power-up.
The switch settings displayed in the table below correspond to the selected address set:
Table for selection of the CAN address set. Source: Sensata Technologies BV
| Switch 1 (IC pin 4) |
Switch 2 (IC pin 3) |
Switch 3 (IC pin 2) |
Switch 4 (IC pin 1) |
Address set |
Notes |
| Off |
Off |
Off |
Off |
1 |
Default |
| Off |
Off |
Off |
On |
2 |
|
| Off |
Off |
On |
Off |
3 |
|
| Off |
Off |
On |
On |
4 |
|
| Off |
On |
Off |
Off |
5 |
|
| Off |
On |
Off |
On |
6 |
|
| Off |
On |
On |
Off |
7 |
|
| Off |
On |
On |
On |
8 |
|
| On |
Off |
Off |
Off |
9 |
|
| On |
Off |
Off |
On |
10 |
|
| On |
Off |
On |
Off |
11 |
|
| On |
Off |
On |
On |
12 |
|
| On |
On |
Off |
Off |
13 |
|
| On |
On |
Off |
On |
14 |
|
| On |
On |
On |
Off |
15 |
|
| On |
On |
On |
On |
16 |
|
Through the CAN interface, the Host (controller) uses the request-response mechanism to connect with the SFP200. The SFP200 provides the requested data in response to a message sent by the host.
Different Extended Message ID values are used to send the SFP200's answer and requests for data from the host. The table below displays these values for the sixteen (16) address sets that the IC supports.
Table for SFP200 supported Message ID sets. Source: Sensata Technologies BV
| Address Set |
Request Message ID |
Response Message ID |
Notes |
| 1 |
0xA100201 |
0xA100200 |
Default Address Set |
| 2 |
0xA100211 |
0xA100210 |
|
| 3 |
0xA100221 |
0xA100220 |
|
| 4 |
0xA100231 |
0xA100230 |
|
| 5 |
0xA100241 |
0xA100240 |
|
| 6 |
0xA100251 |
0xA100250 |
|
| 7 |
0xA100261 |
0xA100260 |
|
| 8 |
0xA100271 |
0xA100270 |
|
| 9 |
0xA100281 |
0xA100280 |
|
| 10 |
0xA100291 |
0xA100290 |
|
| 11 |
0xA1002A1 |
0xA1002A0 |
|
| 12 |
0xA1002B1 |
0xA1002B0 |
|
| 13 |
0xA1002C1 |
0xA1002C0 |
|
| 14 |
0xA1002D1 |
0xA1002D0 |
|
| 15 |
0xA1002E1 |
0xA1002E0 |
|
| 16 |
0xA1002F1 |
0xA1002F0 |
|
Address selection with switches. Image Credit: Sensata Technologies BV
Connectors. Source: Sensata Technologies BV
| Interface |
Manufacturer |
Position |
Part Number |
Description |
| CAN & power on board |
Molex |
4 |
347920040 |
4 pos. header, Shrouded connector (2.00 mm), Through hole tin |
| Can & power mating con. |
Molex |
4 |
347910040 |
Use appropriate crimp contacts (available for AWG 22, 24 and 26) |
| Voltage sensing on board |
Molex |
2 |
039299029 |
MINIFIT JR HDR 02P 94V-0 30AU |
| Voltage sensing mating con. |
Molex |
2 |
039013028 |
MINIFIT JR RCPT DR SIDETABS 2 CKT 94V-0. Crimp contacts available for AWG 18 to 28 |
CAN and Power header & mating connectors. Image Credit: Sensata Technologies BV
Voltage sensing header & mating connectors. Image Credit: Sensata Technologies BV
Molex connectors, part numbers 347920040 and 39299029, are used with the SFP200MOD.
CAN Connector Pinout Description. Source: Sensata Technologies BV
| Pin Number |
Description |
| Pin 1 |
GND |
| Pin 2 |
CAN HIGH |
| Pin 3 |
CAN LOW |
| Pin 4 |
VCC |
Measured Performance Data
Current error across the -40 °C to 125 °C temperature range.
Image Credit: Sensata Technologies BV
Expected Performance Data
SFP Shunt, 108 mm2 bus-bars, 18 μΩ Shunt
This chart shows the results of an efficient thermal shunt model for a transient thermal response study created by Sendyne's modeling team. The model considers particular environmental factors, in this case, open-air conditions.
Choose the present level (for example, 3000 A) and locate where it intersects the desired temperature-rise curve (60 degrees Kelvin), as indicated by the red arrows. Then, follow the junction point down to the time scale; the result is 20 seconds.
With a current of 3000 A, the shunt will heat up to 60 degrees K in 20 seconds. The busbars at the end of this SFP shunt chart have the same cross-section as the shunt (108 mm2). Thanks to these connections, the shunt can sustain 600 A under continuous operation with a temperature rise of less than 100 K.
Estimated Temperature Rise ∆T vs Current and Pulse Duration. Image Credit: Sensata Technologies BV
Expected Performance Data
18 μΩ SFP Shunt with 108 mm2 bus-bars
The results of an efficient thermal shunt model for transient thermal response study, created by Sendyne's modeling team, are shown in this chart. The model considers particular environmental factors, such as outside conditions.
As indicated by the red arrows, choose the current level (for example, 3000 A) and locate the point where it intersects the desired temperature-rise curve (for example, 60 degrees Kelvin); next, follow the intersection point down to the time scale; the result is 20 seconds. The shunt will heat up to 60 degrees K in 20 seconds at a current of 3000 A.
This diagram shows an SFP shunt with busbars at the end with a cross-section of 108 mm2, the same as the shunt itself. With these connections, the shunt can sustain 600 A while operating continuously and rising in temperature by less than 100 K.
Estimated Temperature Rise ∆T vs Current and Pulse Duration. Image Credit: Sensata Technologies BV
SFP200MOD Block Diagram
Image Credit: Sensata Technologies BV