Rf Interface; Charging Control; Digital Interface - Nokia RH-41 Series Technical Documentation Manual

CCS Technical Documentation
The VCORE regulator supplies the DSP and the core part of the UPP. The voltage is pro-
grammable and the startup default is 1.5V. The regulator goes into the low Iq-mode
when in the Sleep mode.
The VR1 regulator uses two LDOs (VR1A and VR1B) and a charge pump. The charge pump
requires one external 1uF capacitor in the Vpump pin and a 220nF flying capacitor
between the CCP and CCN pins. In practice, the 220nF flying capacitor is formed by 2 x
100nF capacitors that are parallel to each other. The VR1A regulator is used by the Taco
RF ASIC.
The VR2 regulator is used to supply the (1) external RF parts, (2) lower band up con-
verter, (3) TX power detector module, and (4) Taco. In light load situations, the VR2 regu-
lator can be set to the low Iq-mode.
The VR3 regulator supplies the VCTCXO and Taco in the RF. It is always enabled when the
UEM is active. When the UEM is in the Sleep mode, the VR3 is disabled.
The VR4 regulator supplies the RX frontends (LNA and RX mixers).
The VR5 regulator supplies the lower band PA. In light load situations, the VR5 regulator
can be set to the low Iq-mode.
The VR6 regulator supplies the higher band PA and TX amplifier. In light load situations,
the VR6 regulator can be set to the low Iq-mode.
The VR7 regulator supplies the VCO and Taco. In light load situations, the VR7 regulator
can be set to the low Iq-mode.
The IPA1 and IPA2 are programmable current generators. A 27Ω/1%/100ppm external
resistor is used to improve the accuracy of the output current. The IPA1 is used by the
lower PA band and IPA2 is used by the higher PA band.

RF Interface

The interface between the baseband and the RF section is also handled by the UEM. It
provides A/D and D/A conversion of the in-phase and quadrature receive and transmit
signal paths. It also provides A/D and D/A conversions of received and transmitted audio
signals to and from the UI section. The UEM supplies the analog AFC signal to the RF sec-
tion, according to the UPP DSP digital control.

Charging Control

The CHACON block of the UEM asics controls charging. The needed functions for the
charging controls are the (1) pwm-controlled battery charging switch, (2) charger-moni-
toring circuitry, (3) battery voltage monitoring circuitry, and (4) RTC supply circuitry for
backup battery charging (Not used in RH-41). In addition to these, external components
are needed for EMC protection of the charger input to the baseband module.

Digital Interface

Data transmission between the UEM and the UPP is implemented using two serial con-
Issue 2 09/2003
Nokia Corporation
Confidential
RH-41
System Module
Page 13