EZZE SL900A, Technical Manual

Page: 51 / 116

M
ODEL
SL900A V
ERSION
V_1.0
P
REPARED BY
H/W D
ATE
2006.06.30
S
UBJECT
T
ECHNICAL
M
ANUAL
P
AGE
31/51
SL900A T
ECHNICAL
M
ANUAL
The following table is shown the used pin for RF part.
Pin Name Pin Description Description Component
BPI_BUS 0 HB_TX Switch Module DCS/PCS TX Switch Module(LMSP54HA)
BPI_BUS 1 LB_TX Switch Module GSM TX Switch Module(LMSP54HA)
BPI_BUS 2 PCS Switch Module PCS RX Switch Module(LMSP54HA)
BPI_BUS 4 PA_EN PAM Enable PAM (RF3146)
BPI_BUS 5 BANDSW_DCS Band switch for DCS PAM (RF3146)
BPI_BUS 8 BT_LDO_EN Blue Tooth Power Supply Enable BTM(CR222)
BPI_BUS 9 RFVCOEN RF VCO Enable Transceiver(MT6129)
8.3 Automatic Power Control Unit
Automatic Power Control unit is used to control the Power Amplifier module. Through APC unit, we can set the
proper transmit power level of the handset and to ensure that the burst power ramping requirements are met. In
one TDMA frame, up to 7 TDMA events can be enabled to support multi-slot transmission. In practice, 5 banks
of ramp profiles are used in one frame to make up 4 consecutive transmission slots.
The shape and magnitude of the ramp profiles are configurable to fit ramp-up, intermediate ramp, and ramp-
down profiles. Each bank of the ramp profile consists of 16 8-bit unsigned values, which is adjustable for
different conditions.
The entries from one bank of the ramp profile are partitioned into two parts, with 8 values in each part. In
normal operation, the entries in the left half part are multiplied by a 10-bit left scaling factor, and the entries in
the right half part are multiplied by a 10-bit right scaling factor. Those values are then truncated to form 16 10-
bit intermediate values. Finally the intermediate ramp profile are linearly interpolated into 32 10-bit values and
sequentially used to update to the D/A converter. The block diagram of the APC unit is shown in Figure 28.
Figure 28. Block diagram of APC unit
In SL900A, The APC Analog Signal is inputted to Power Amplifier Module through Low Pass filter
(R400,C406)
The APC Analog Signal has 32 Ramp profiles for Up Ramp and Down Ramp each 16 profiles.
The Figure 29 shown the Timing Mask for Normal VAPC.