User manual

LPC3250 Developer’s Kit v2 - User’s Guide

Page 16

4.1 Modifications to OEM Base Board

The OEM Base Board has been designed to be flexible. Most options can be controlled via jumpers

but some options might need soldering. Note that modifications to the board are done at own risk and

void all warranties.

4.2 SP2: OEM Board Connector

The LPC3250 OEM board connector is a standard DDR2 SO-DIMM socket with 200 positions and

0.6mm pitch. The JEDEC standard for this form factor is called MO-224. It has 1.8V keying (which is

what DDR2 stands for).

4.3 SP2: Current Measurements

It is possible to accurately measure current consumption of the LPC3250 OEM board. This can be very

valuable when working with applications that make use of the low power modes of the LPC3250

processors. The circuit is based on the chip ZXCT1010 from Diodes/Zetex. This chip generates a

voltage output proportional to the current through R2. This voltage can be measured over J2. 100mA

gives a 500mV output voltage, or expressed differently, 1mV correspond to 0.2mA

It is possible to remove R1, R2 and/or R3 for measuring current with an external multimeter. Note that

VCC_MAIN and VCC_BUFFERS are separate power supplies on the LPC3250 OEM board. The

combined current is measured over R2 but each of the supplies can also be measured over R1 and

R3, respectively.

Figure 2 – Current Measurement J2

4.4 SP3: Expansion Connectors

All relevant OEM board signals are available for external use via three 64 pos IDC expansion

connectors; J3, J4 and J5. The expansion connectors are close to the SO-DIMM connectors to

minimize signal distortion.

Note that some OEM board circuits may need to be disconnected before externally used. Carefully

investigate the need for this before using a signal for external expansion.

Note that J4 has gathered all needed signals for expanding the memory bus (16-bit bus expansion). J4

is the expansion connector closest to the board edge.

Current Measurement

J2 (left: signal, right: gnd)