SILICON LABS CONFIDENTIAL
Si3402-A-GM to Si3402-B-GM EVB Modifications
Version 0.4
The Si3402-B-GM device requires component value changes from those used with the Si3402-A-GM
evaluation board (EVB) reference design. Table 1 below is a summary of the required modifications.
Following Table 1 are two reference schematic excerpts showing the locations of the modified
component values for both the isolated (flyback) and non-isolated (buck) topologies.
Table 1. Si3402-B-GM EVB modifications versus the Si3402-A-GM EVB
Application design effect
Detect resistor value
change
The former 25.5kΩ detect resistor must be replaced by 24.3kΩ
1%
Classification resistor value
change
The following 1% resistors must be used:
Class0: 681.00 or higher (It is optional to place this resistor)
Class1: 140.0
Class2: 75.0
Class3: 48.7
Class4: 33.2
ISO EVB DCDC 3.3V changes
C8, R9 & C23 are not need—Do not populate them.
C9=10nF, C21=33nF, R12=475 Ω & R8=1.1k Ω
Replace D2 (DFLT15A) with DFLT30A
* See Revision Notes
C8, R9 & C23 are not need—Do not populate them.
C9=3.3nF, C21=15nF, R12=0 & R8=0 (place zero Ω resistors)
Replace D2 (DFLT15A) with DFLT30A
ISO EVB DCDC 12V changes
Flyback
C8, R9 & C23 are not need—Do not populate them.
C9=10nF, C21=15nF, R12=0, R8=0 (place zero Ω resistor)
R7=3k
Replace D2 (DFLT15A) with DFLT30A
DCDC reference voltage
change (Buck case only)
Now 1.35V instead of previous 1.23V. Thus, R5 changes from
2.87kΩ 1% to 3.24kΩ 1%. R6 (1%) is modified according to this
table:
