Hitachi, Ltd. (TSE: 6501) today announced the HD155131TF highly-integrated IC,
implementing transmit/receive signal processing in RF block*1 for dual-band of digital
cellular standards GSM-900 and DCS-1800/1900*2in a single chip. Sample shipments will
begin in January 2000 in Japan.
The HD155131TF incorporates a dual-PLL*3 synthesizer plus LNA*4 for 900MHz and
1800MHz band on the receiving side, and enables the VCO*5 tuning band to be minimized
through the use of double superheterodyne*6 technology, allowing a flexible frequency plan
to be designed. In addition, an offset PLL system is used for frequency conversion on the
transmitting side, making a system antenna block duplexer*7 unnecessary, and so eliminating
the power loss associated with a duplexer.
Use of the HD155131TF simplifies the design of a digital cellular system supporting the
GSM-900 and DCS-1800/1900 standards, and enables system size, cost, and power
consumption to be reduced.
The GSM-900 and DCS-1800/1900 are the standards of a digital cellular system that was
chiefly developed and constructed in Europe, and now has an expanding market, having been
introduced into various regions of the world including Asia, the Middle East, and Africa.
In response to the shortage of GSM channels in large cities, services have recently been
introduced that allow both bands of the GSM-900 and DCS-1800/1900 standards to be used
by a single terminal. This has led to a sharp shift in demand from single terminals, which
support separate bands individually, to dual terminals supporting both bands in one terminal.
In 1999, a new system--GPRS (General Packet Radio System)--was standardized with the
aim of speeding up data transfer on GSM terminals, and a GSM system service using the
1,900 MHz band was started in cities throughout the United States, leading to hopes for the
development of high-frequency ICs capable of handling the 900/1,800/1,900 MHz bands.
These developments have brought demands for even smaller and lighter portable phones, with
long operating times, and also for higher levels of integration-to reduce the mounting area-
and lower cost for the electronic components installed in these phones.
In response to these needs, Hitachi entered the market with the HD155101BF and
HD155121F GSM high-frequency block signal processing ICs, developed jointly with GSM
system consultants TTP Communications Ltd. of the United Kingdom. These have now been
followed by the development of the HD155131TF, transmit/receive signal processing IC in
RF block capable of handling GPRS plus GSM-900 and DCS-1800/1900 standards frequency
bands.
The HD155131TF uses a 0.35 um BiCMOS process, and integrates most of the RF block
functions in a single chip using SOI (Silicon On Insulator) technology and a deep-groove
separation structure.
On the transmitting side, out-of-band noise has been reduced through the use of an offset PLL
system, the number of parts has been reduced, including the SAW filter*8 and duplexer
previously required in the antenna block. In addition, Gain characteristics of the PGA*9
circuit has a 98 dB dynamic range and good linearity, enabling controlled by the baseband
block*10 that is connected through serial interface .
In the frequency plan designed for the GSM-900 and DCS-1800/1900, the tuning band needed
for the IF and RF oscillators has been minimized by using the same IF*11. A low-power-
consumption design has been adopted, with a low operating voltage range of 2.7 V to 3.3 V,
and current dissipation of 45 mA when transmitting, 60 mA when receiving, and 1 uA or less
in power save mode.
The use of a TQFP-56 package, allowing compact mounting, enables portable phones to be
made smaller and lighter by reducing the required mounting area.
Notes: 1. RF block: Radio Frequency block. The block that processes high-frequency
signals.
2. GSM: Global System for Mobile Communications. A European 900 MHz
band digital cellular phone system.
DCS-1800/1900: Digital Cellular System, 1800 MHz/1900 MHz band.
Cellular phone system using the same method as GSM in 1,800/1,900 MHz
band area. DCS-1800 is also known as PCN (Personal Communications
Network).
3. PLL: Phase Locked Loop. A circuit technology that provides oscillation at an
arbitrary frequency through the configuration of a loop circuit that
synchronizes frequency phases. Also refers to the circuit itself.
4. LNA: Low Noise Amplifier
5. VCO: Voltage Controlled Oscillator. An oscillator whose output frequency
varies according to an input control voltage. An important component that
affects wireless circuit quality.
6. Double superheterodyne: A method whereby wireless frequency signals
undergo frequency conversion twice in the reception system of a wireless
device, and are converted to the baseband frequency.
7. Duplexer: A wave divider. Contains two filters, for the receiving frequency
and the transmitting frequency, and carries out mutual separation. Versions
with switches are also available.
8. SAW filter: Surface Acoustic Wave filter. A filter that uses surface acoustic
waves conveyed along the surface of a piezoelectric material. Implements a
filter that takes the resonance frequency and its vicinity as the pass band.
9. PGA: Programmable Gain Control Amplifier
10. Baseband block: Digital signal processing block that performs codec
processing and system control, including voice signal AD/DA conversion, and
man-machine interface and transmit/receive signal channel timing.
11. IF: Intermediate Frequency
< Typical Applications >
Digital cellular phone based on GSM-900,DCS-1800/1900 standards
< Prices in Japan > (For Reference Only)
Product Code Sample Price (Yen)
HD155131TF 1,000
< About TTP Communications Ltd.>
TTP Communications Ltd., based in Cambridge, U.K., undertakes worldwide consultancy on
product development, including software and hardware. The company has extensive
experience in the area of GSM system development, undertaking consultancy work
worldwide.
< Specifications >
Item Specifications
Operating voltage range 2.7 V to 3.3 V
Operating temperature range -20 to +75 degrees Celsius
Current dissipation GSM-900, Receiving 60 mA typ.
(Power supply voltage is DCS-1800/1900 Transmitting 45 mA typ.
3V.) mode
Power save mode 1 uA max.
Operating frequency GSM-900 mode Receiving 925 to 960 MHz
Transmitting 880 to 915 MHz
DCS-1800/1900 Receiving 1805 to 1990 MHz
mode Transmitting 1710 to 1910 MHz
PGA gain range -40 to 58 dB typ.
Transmission-side Carrier -40 dBc typ. -31 dBc min.
spurious suppression Sideband -40 dBc typ. -35 dBc min.
ratio
Transmission-side GSM-900 mode 925 MHz -155 dBc/Hz typ.
out-of-band noise 935 MHz -165 dBc/Hz typ.
DCS-1800/1900 mode 1805 MHz -156 dBc/Hz typ.
Package TQFP-56
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