EEWORLDEEWORLDEEWORLD

Part Number

Search

U2894B

Description
Modulation PLL for GSM, DCS and PCS Systems
File Size578KB,16 Pages
ManufacturerTEMIC
Websitehttp://www.temic.de/
Download Datasheet View All

U2894B Overview

Modulation PLL for GSM, DCS and PCS Systems

U2894B
Modulation PLL for GSM, DCS and PCS Systems
Description
The U2894B 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 U2894B is designed for cellular phones such as
GSM900, DCS1800, and PCS1900, applying a
transmitter architecture at which the VCO operates at the
TX output frequency. No duplexer is needed since the out-
of-band noise is very low. The U2894B exhibits low
power consumption. Broadband operation gives you high
flexibility for multi-band frequency mappings. The IC is
available in a shrinked small-outline 28-pin package
(SSO28).
The U2893B offers the same functionality with other
divider ratios.
Electrostatic sensitive device.
Observe precautions for handling.
Features
D
D
D
D
D
D
D
Supply voltage range 2.7 V to 5.5 V
Current consumption 50 mA
Power-down functions
High-speed PFD and charge pump (CP)
Small CP saturation voltages (0.5/0.6 V)
Programmable dividers and CP polarity
Low-current standby mode
Benefits
D
Novel TX architecture saves filter costs
D
Extended battery operating time without duplexer
D
Less board space (few external components)
D
VCO control without voltage doubler
D
Small SSO28 package
D
One device for all GSM bands
Block Diagram
I NI
1
2
MDLO Q NQ PUMIX PU MIXO MIXLO
3
28 27
12
19
25
20
22
23
90°
MDO
NMDO
5
6
+
I/Q modulator
16
17
13
14
R 1
divider
N 1
divider
MUX
Voltage
reference
Mixer
RF
NRF
8
ND
NND
RD
NRD
VSP
PFD
Charge
pump
9
CPO
7
21
VS1
VS2
VS3
MC
15
Mode
control
4
18
24
11
CPC
10
GNDP
GND
Figure 1. Block diagram
26
12494
Rev. A4, 30-Sep-98
1 (16)

EEWorld
subscription
account

EEWorld
service
account

Automotive
development
circle

Robot
development
community

Index Files: 1504  397  1582  1543  1637  31  8  32  33  3 
Datasheet   0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Room 1530, 15th Floor, Building B, No. 18 Zhongguancun Street, Haidian District, Beijing Telephone: (010) 82350740 Postal Code: 100190
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved 京ICP证060456号 京ICP备10001474号-1 电信业务审批[2006]字第258号函 京公网安备 11010802033920号