1998 Nov 19
2
Philips Semiconductors
Product specication
Low-voltage frequency synthesizer for
radio telephones
UMA1021AM
FEATURES
Low phase noise
Low current from 3 V supply
Fully programmable main divider
3-line serial interface bus
Independent fully programmable reference divider,
driven from external crystal oscillator
Hard and soft power-down control.
APPLICATIONS
900 MHz and 2 GHz mobile telephones
Portable battery-powered radio equipment.
GENERAL DESCRIPTION
The UMA1021AM BICMOS device integrates a prescaler,
programmable dividers, and a phase comparator to
implement a phase-locked loop.
The device is designed to operate from 3 NiCd cells, in
pocket phones, with low current and nominal 3 V supplies.
The synthesizer operates at RF input frequencies
up to 2.2 GHz with a fully programmable reference divider.
All divider ratios are supplied via a 3-wire serial
programming bus.
Separate power and ground pins are provided to the
analog (charge pump) and digital circuits. The ground
leads should be externally short-circuited to prevent large
currents flowing across the die and thus causing damage.
VDD1 and VDD2 must also be at the same potential (VDD).
VCC must be equal to or greater than VDD for wider control
range of the Voltage Controlled Oscillator (VCO),
e.g. VDD = 3 V and VCC =5V.
The charge pump current (phase detector gain) is fixed by
an external resistor at pin ISET and controlled via the serial
interface. Only a passive loop filter is necessary; the
charge pump functions within a wide voltage compliance
range to improve the overall system performance.
QUICK REFERENCE DATA
ORDERING INFORMATION
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
VDD1, VDD2
digital supply voltage
VDD1 =VDD2 =VDD
2.7
5.5
V
VCC
analog supply voltage for charge pump VCC ≥ VDD
2.7
5.5
V
Itot
total supply current (IDD +ICC)VCC =VDD = 5.5 V
10
mA
Itot(pd)
total supply current in Power-down
mode (IDD +ICC)
logic levels 0 V or VDD
5
A
fRF
RF input frequency
300
2200
MHz
fxtal
crystal reference oscillator input
frequency
3
35
MHz
fph(comp)
phase comparator frequency
200
kHz
Tamb
operating ambient temperature
30
+85
°C
TYPE NUMBER
PACKAGE
NAME
DESCRIPTION
VERSION
UMA1021AM
SSOP16
plastic shrink small outline package; 16 leads; body width
4.4 mm
SOT369-1