SI85XX-EVB Silicon Laboratories Inc, SI85XX-EVB Datasheet - Page 21

• Manufacturer Part Number: SI85XX-EVB
• Description: BOARD EVAL CURRENT SENSOR 10A
• Manufacturer: Silicon Laboratories Inc

Specifications of SI85XX-EVB

• Sensor Type: Current Sensor
• Sensing Range: 10A
• Interface: Analog
• Voltage - Supply: 2.7 V ~ 5.5 V
• Embedded: No
• Utilized Ic / Part: Si8512
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed
• Other names: 336-1425

3.4. Single-Phase Buck Converter Example
In this example, the Si850x is configured to operate in a single-phase synchronous buck converter (Figure 17).
This converter has a PWM frequency of 1 MHz and a maximum duty cycle of 80%.
This is an example of a half-wave application that can be addressed with Single-Ended output mode. The PWM
period is calculated to be 1/10
maximum duty cycle (R
In this example, the current measurement is made when the buck switch is on; so, PH2 is chosen as the reset
signal by connecting PH2 to R1 and grounding R2 and R3. The PH2 signal can be obtained at the input of the
driver external to the PWM controller or the output of the controller's internal driver (through a resistor divider if the
driver output swings beyond the device VDD range).
0.1 µF
C1
PH2
TRST
1 µF
C2
R
TRST
= 20 k).
Figure 17. Si850x Single-Phase Buck Converter
PH1
VDD1
TRST
–6
R2
R1
= 1.0 µs, and the worst-case value, t
VDD
VDD2
Si850x
IOUT
VIN
IIN
Preliminary Rev. 0.21
Q1
L1
Q2
GND2
GND1
GND3
OUT
C3
VOUT
Si850x State
R
, is 0.2 x 1.0 x 10
Current
PH2
2 Vpp
RESET
100 ns
PWM
I = 0
MEASURE
–6
I > 0
= 200 ns at 80%
Si85xx
21