U2893B
Modulation PLL for GSM, DCS and PCS Systems
Description
The U2893B is a monolithic integrated circuit. It is
realized using TEMIC’s advanced silicon bipolar UHF5S
technology. The device integrates a mixer, an I/Q modu-
lator, a phase-frequency detector (PFD) with two
synchronous-programmable dividers, and a charge pump.
The U2893B is designed for cellular phones such as GSM,
DCS1800, and PCS1900, applying a transmitter-archi-
tecture where the VCO is operated at the TX output
frequency.
U2893B exhibits low power consumption, and the power-
down function extends battery life.
The IC is available in a shrinked small-outline 28–pin
package (SSO28).
Features
D
Supply voltage down to 2.7 V
D
Current consumption 40 mA
D
Power-down function
D
Low-current standby mode
D
High-speed PFD and charge pump
D
Integrated dividers
Benefits
D
D
D
D
D
High-level RF integration
TX architecture saves filter costs
Low external part count
Small SSO28 package
One device for various applications
Block Diagram
MDLO
I
NI
Q NQ
PUMIX
PU MIXO
MIXLO
MDO
NMDO
+
90
grd
Voltage
reference
Mixer
RF
NRF
I/Q modulator
N:1
divider
R:1
divider
Mode
control
GND
CPC GNDP
MUX
PFD
VSP
CPO
VS1
VS2
VS3
ND
NND
RD
NRD
MC
12494
Figure 1. Block diagram
TELEFUNKEN Semiconductors
Rev. A1, 29-Jan-97
1 (14)
Preliminary Information
TEMIC [ TEMIC SEMICONDUCTORS ]
