User Guide

CC Technical Documentation System Module

NPM-10 (3595)

The SIM interface is located in the two ASICs: UPP and UEM.

The SIM interface in the UEM contains power up/down, port gating, card detect, data

receiving, ATR-counter, registers, and level-shifting buffers logic. The SIM interface is the

electrical interface between the Subscriber Identity Module Card (SIM Card) and mobile

phone (via the UEM device).

The data communication between the card and the phone is asynchronous half-duplex.

The clock supplied to the card is 3.25 MHz. The data baud rate is SIM card clock

frequency divided by 372 (by default), 64, 32, or 16. The protocol type that is supported

is T=0 (asynchronous half-duplex character transmission as defined in ISO 7816-3).

The internal clock frequency from the UPP CTSI block is 13 MHz in GSM. To achieve the

minimum starting SIMCardClk rate of 3.25 MHz (as is required by the authentication

procedure) and the duty cycle requirement of between 40% and 60%, the slowest

possible clock supplied to the SIM has to be in the GSM system clock rate of 13/4 MHz.

Internal Audio

Earpiece

NPM-10 (3595) uses the standard DCT3 13 mm earpiece. The earpiece design is

leak-tolerant.

The internal earpiece is a dynamic earpiece with an impedance of 32Ω. The earpiece is a

low-impedance type, since the sound pressure is to be generated using current and not

voltage (supply voltage is restricted to 2.7 V). The earpiece is driven directly by the UEM;

the earpiece driver in the UEM is a bridge amplifier.

Figure 6: Speaker Interface

Internal Microphone

NPM-10 (3595) uses an omnidirectional microphone that is located in the system

connector, sealed in a rubber gasket. The microphone is biased from the UEM MICB1 out-

put and lowpass filtered through an RC filter (470_,22uF) giving 20 dB attenuation at

217 Hz. The signal path from the microphone is lowpass filtered (2.2k_,1nF) and EMC

decoupled (22 pF)

The two 33nF capacitors are used to create a 1st order high-pass filter. The input

impedance of the gain stage at MIC1P/N is the other part of the RC circuit. The high-

pass filter is required due to low-frequency noise, which is one phenomenon identified as

a problem when the internal microphone is used as hands-free microphone (PPH-1/car

kit mode).

EARN

EARP

EARN

UEM