UMA1021AM Datasheet, PDF (2/16 Pages) NXP Semiconductors – Low-voltage frequency synthesizer for radio telephones

Philips Semiconductors
Low-voltage frequency synthesizer for
radio telephones
Product specification
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.
V_DD1 and V_DD2 must also be at the same potential (V_DD).
V_CC must be equal to or greater than V_DD for wider control
range of the Voltage Controlled Oscillator (VCO),
e.g. V_DD = 3 V and V_CC = 5 V.
The charge pump current (phase detector gain) is fixed by
an external resistor at pin I_SET 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
SYMBOL
V_DD1, V_DD2
V_CC
I_tot
I_tot(pd)
f_RF
f_xtal
f_ph(comp)
T_amb
PARAMETER
CONDITIONS
digital supply voltage
V_DD1 = V_DD2 = V_DD
analog supply voltage for charge pump V_CC ≥ V_DD
total supply current (I_DD + I_CC)
V_CC = V_DD = 5.5 V
total supply current in Power-down
mode (I_DD + I_CC)
logic levels 0 V or V_DD
RF input frequency
crystal reference oscillator input
frequency
phase comparator frequency
operating ambient temperature
MIN.
2.7
2.7
−
−
300
3
−
−30
TYP.
−
−
10
5
−
−
200
−
MAX. UNIT
5.5 V
5.5 V
−
mA
−
µA
2200 MHz
35
MHz
−
kHz
+85 °C
ORDERING INFORMATION
TYPE NUMBER
UMA1021AM
NAME
SSOP16
PACKAGE
DESCRIPTION
plastic shrink small outline package; 16 leads; body width
4.4 mm
VERSION
SOT369-1
1998 Nov 19
2