User`s guide
System Operation
© 2008 Microchip Technology Inc. DS70320B-page 71
4.1.4.3 PROGRAMMING CONNECTIONS
The SMPS AC/DC Reference Design comes pre-programmed with the control software 
and does not require a programmer to be connected to the system. However, ICSP™ 
headers are provided on the primary and secondary side for software development and 
testing.
Figure 4-6 shows the location of the primary side programming header (J2 on the 
control board).
FIGURE 4-6: PRIMARY SIDE PROGRAMMING HEADER
Figure 4-7 shows the location of the secondary side programming header (J1 on the 
control board).
FIGURE 4-7: SECONDARY SIDE PROGRAMMING HEADER
The secondary side ICSP header is isolated from the AC Mains, so there are no special 
precautions necessary when programming the device.
Primary Side
ICSP™ Header
CAUTION
The primary side ICSP header (J2) is not isolated from the AC Mains. An isolated USB 
hub must be used to connect the programmer to the computer's USB port. If the power 
supply of the SMPS AC/DC Reference Design is not isolated before programming the 
device, ensure that the computer is isolated or removed from the grid. 
Secondary Side
ICSP™ Header










