# Calculating the voltage difference between a switching pin out and a constant Vout

Sorry to trouble you all with a similar question. But this is a different question altogether regarding calculation of voltage difference. I am using NCV3063 IC.

According to my design of the boost converter in my board, I am measuring the values of pin1 and pin2 in multimeter and scope respectively. This is a reference board.

For Vin(Vcc) of 16V, The voltage at pin1(SWC) of the IC is 5.05V as measured in DMM.

1. Pin2 (SWE), I am measuring in scope, I am getting a peak-peak of some 15.8V with 30.6% duty and max amplitude of 13.8V.
2. Now, Vswce=difference between the pins 1 and 2.

How to calculate the voltage difference between (1) and(2)?

Or in general, how to calculate the voltage difference between a switching Vout pin (here, pin2) and a constant Vout pin (here, pin1).

Please help

Thanks

• You should include the schematic of your boost converter. – Bimpelrekkie Jan 29 at 14:33
• As pointed out in comments provide a schematic this can probably be taken from the IC data sheet or application note. Also provide links to the data sheet and if applicable application note. – Warren Hill Jan 29 at 15:17

## 1 Answer

From Spec

VSWCE(DROP) Darlington Switch Collector to Emitter Voltage Drop
(ISW = 1.0 A, Pin 2 to GND, TJ = 25°C)
1.0Vtyp 1.3 Vmax
Note 7. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as possible

This implies Rce= 300 mohms + 0.8V of Vbe or using linear regression,
Vce= 0.8 + Ic * 0.3Ω 