Data Sheet
Skyworks Preliminary
Doc. No. 101118B
Proprietary Information and Specifications Are Subject to Change
October 29, 2001
RF25F
Tx ASIC for CDMA/AMPS and PCS Applications
The RF25F Transmit Application-Specific Integrated Circuit (ASIC) is a tri-mode,
dual-band upconverter and driver amplifier in a 5x5 mm LGA package designed for
transmitter application in portable phones. The RF25F can be used in both cellular
and Personal Communications System (PCS) bands and, in dual-mode, can be
used in both Code Division Multiple Access (CDMA) mode and Advanced Mobile
Phone System (AMPS) mode.
The RF25F device includes the following functional blocks:
Cellular and PCS upconverters with RF gain control.
Cellular and PCS power amplifier drivers.
The device package and pin-outs are shown in Figure 1. A block diagram of the
RF25F is shown in Figure 2.
Features
Supports tri-mode, dual-band applications
Optional 14 dB mixer RF adjustable gain
Low DC power dissipation
Dual drivers for cellular and PCS bands
32-pin Land Grid Array (LGA) 5x5 mm package
Applications
Cellular and PCS band phones
CDMA and AMPS modes in the cellular band
including:
-
CDMA-US
-
CDMA-J
CDMA mode in the PCS band including:
-
US-PCS
-
K-PCS
C872
VCC_DRV_BIAS
IDLE
VCC_LAST_DRV_PCS
POT_CELL
DRV_ON
NC
RF_PCS_OUT
NC
RF_CELL_OUT
25
24
23
22
21
20
19
18
17
CELL/PCS
VCC_DR
V_800
PO
T_PCS
NC
VCC_1ST_DR
V_PCS
DR
V_CELL_IN
DR
V_PCS_IN
32
31
30
26
29
28
27
VCC_MIX
LO_CELL_IN
LO_PCS_IN
IF_130_IN+
AMPS/CDMA
VCC_IF
IF_130_IN
10
11
12
16
13
14
15
NC
RF_GC
VCC_DIFF_DRV_BIAS
MIX_CELL_OUT
NC
VCC_DIFF_DRV
NC
MIX_PCS_OUT
NC
1
2
3
4
5
6
7
8
9
Figure 1. RF25F Pinout 32-Pin LGA
(Top View)
RF25F
Tx ASIC for CDMA/AMPS/ and PCS Applications
2
Skyworks Preliminary
101118B
Proprietary Information and Specifications Are Subject to Change
October 29, 2001
C429
RF_CELL_OUT
RF_PCS_OUT
Cell SAW
PCS SAW
Power
Management
LO_PCS_IN
Idle
RF Gain
Control
LO_CELL_IN
IF+ IF-
Lo Buf
Lo Buf
AMPS/CDMA
DRIVER_ON
31
29
21
14
5
9
7
17
16
24
30
10
2
26
27
Cell/PCS
Figure 2. RF25F Tx ASIC Block Diagram
Technical Description
The RF25F is an upconverter and driver amplifier used by the
CDMA transmitter section in the cellular and PCS bands. Its
function can also be used in AMPS mode. A band select
command chooses between the cellular and the PCS band. A
mode select command chooses between CDMA and AMPS
mode in the cellular band. The ASIC consists of two variable
gain upconverters and two power amplifier drivers for the
cellular and PCS bands.
Upconverters. The cellular and PCS variable gain upconverters
receive the IF signal. Each upconverter uses an external Local
Oscillator (LO) controlled by an external Phase Locked Loop
(PLL). Upconverter conversion gain control can be used to
calibrate out part-to-part and temperature gain variations in the
transmit path. A band select command switches between the
cellular and PCS bands. The DRIVER_ON command
deactivates the driver during no transmission status. The output
RF signal is sent to an output pin to be filtered before driver
amplification.
Power Amplifier Drivers. Two power amplifier drivers are
included, the cellular driver and the PCS driver.
Each driver takes its input from the upconverter after passing
through an image reject filter. The drivers amplify the signal and
send it to an external power amplifier.
The DRIVER_ON command is used during gated output power
mode to deactivate the drivers in periods of no transmission. A
Surface Acoustic Wave (SAW) filter for noise and image
rejection should be placed between the driver and the external
power amplifier.
Electrical and Mechanical Specifications
Signal pin assignments and functional pin descriptions are
described in Table 1. The absolute maximum ratings of the
RF25F are provided in Table 2. The recommended operating
conditions are specified in Table 3 and electrical specifications
are provided in Table 4.
Typical performance characteristics of the RF25F are illustrated
in Figures 3 through 26. Figure 27 provides a typical application
schematic diagram. Figure 28 shows the package dimensions
for the 32-pin LGA and Figure 29 provides the tape and reel
dimensions.
Tx ASIC for CDMA/AMPS/ and PCS Applications
RF25F
101118B
Skyworks Preliminary
3
October 29, 2001
Proprietary Information and Specifications Are Subject to Change
Electrostatic Discharge (ESD) Sensitivity
The RF25F is a Class 1 device. The following extreme
Electrostatic Discharge (ESD) precautions are required
according to the Human Body Model (HBM):
Protective outer garments.
Handle device in ESD safeguarded work area.
Transport device in ESD shielded containers.
Monitor and test all ESD protection equipment.
The HBM ESD withstand threshold value, with respect to
ground, is
2.5 kV. The HBM ESD withstand threshold value,
with respect to VDD (the positive power supply terminal) is also
2.5 kV.
Table 1. RF25F Signal Descriptions (1 of 2)
Pin #
Name
Description
1
VCC_DRV_BIAS
Supply voltage for bias circuit of cellular driver and last stage of PCS driver.
2
IDLE
Upconverter enable signal. When the input is low, the chip is disabled. When the input is
high, the chip is enabled.
3
VCC_LAST_DRV_PCS
Supply voltage for the PCS driver amplifier. This pin can be used to turn the last driver
on and off for a 24 dB gain step.
4
POT_CELL
This pin is connected to an external resistor. The value of the resistor sets the bias
current of the cellular driver, which affects gain and Adjacent Channel Power
Rejection(ACPR).
5
DRV_ON
This is the driver control signal. When the pin is low, the driver is deactivated during no
transmission. During transmission the pin should be high to enable the driver.
6 NC
No
connection.
7
RF_PCS_OUT
This is the output pin for the PCS RF signal. The pin is connected to the output of the
PCS driver amplifier. Impedance matching is required.
Vcc
8 NC
No
connection.
9
RF_CELL_OUT
This is the output pin for the cellular RF signal. The pin is connected to the output of the
cellular driver amplifier. Impedance matching is required.
Vcc
10
CELL/PCS
This is a control signal input pin that selects between the cellular band and PCS band.
When the input is low, the cellular band is chosen. When the input is high, the PCS
band is chosen.
11
VCC_DRV_800
Supply voltage for the driver of the cellular band.
12
POT_PCS
This pin is connected to an external resistor. The value of the resistor sets the bias
current of the PCS driver, which affects gain and ACPR.
13
VCC_1ST_DRV_PCS
Supply voltage for the first amplifier in the PCS driver block.
14
DRV_CELL_IN
The cellular driver input pin connected to the RF input of the cellular band driver. The
input signal should pass through a SAW filter before being connected to the driver.
Impedance matching is required.
15
DRV_PCS_IN
The PCS driver input pin connected to the RF input of the PCS band driver. The input
signal should pass through a SAW filter before being connected to the driver.
Impedance matching is required.
Vcc
+
16 NC
No
connection.
RF25F
Tx ASIC for CDMA/AMPS/ and PCS Applications
4
Skyworks Preliminary
101118B
Proprietary Information and Specifications Are Subject to Change
October 29, 2001
Table 1. RF25F Pin Assignments and Signal Descriptions (2 of 2)
Pin #
Name
Description
17 NC
No
connection.
18
MIX_PCS_OUT
This pin is connected to the RF output of the PCS upconverter. This pin needs
impedance matching. The RF output signal should be routed through an image rejection
filter before being connected to the driver input.
Vcc
19 NC
No
connection.
20
VCC_DIFF_DRV
Supply voltage for a differential amplifier in the upconverter block.
21 NC
No
connection.
22
MIX_CELL_OUT
This pin is connected to the RF output of the cellular upconverter. The RF output signal
should be routed through an image rejection filter before being connected to the cellular
driver input.
Vcc
23
VCC_DIFF_DRV_BIAS
Supply voltage for the bias circuit of both upconverters' differential drivers.
24
RF_GC
The gain control pin for both RF upconverters.
25 NC
No
connection.
26
IF130_IN+
The IF input pin for the upconverter block. DC bias is set internally.
27
IF130_IN
Same as pin 26, except a complementary input.
+
28
VCC_IF
Supply voltage for the IF mux and bias circuitry.
29
AMPS/CDMA
This is the cellular mode control signal input. When the input is low, the AMPS mode is
selected. If the input is high, CDMA mode is selected.
30
LO_PCS_IN
This is the input pin for the PCS band local oscillator. A typical 10 dBm LO power is
needed.
31
LO_CELL_IN
This is the input pin for the cellular band local oscillator. A typical 10 dBm LO power is
needed.
32
VCC_MIX
Supply voltage for the mixer and LO buffer of the upconverter block.
Tx ASIC for CDMA/AMPS/ and PCS Applications
RF25F
101118B
Skyworks Preliminary
5
October 29, 2001
Proprietary Information and Specifications Are Subject to Change
Table 2. Absolute Maximum Ratings
Parameter Minimum
Maximum
Units
Supply voltage (VCC)
0.3
+5.0
V
Input voltage range
0.3
VCC
V
Power dissipation
600
mW
Operating temperature
30
+80
C
Storage temperature
40
+125
C
Table 3. Recommended Operating Conditions
Parameter Minimum
Typical
Maximum
Units
Supply voltage (Note 1)
2.85
3.0
3.3
V
Logic level high
Vcc 0.5
V
Logic level low
0.5
V
Supply current in 800 MHz CDMA @ 7 dBm
62
71
mA
Supply current in 800 MHz CDMA @ 0 dBm
52
59
mA
Supply current in 800 MHz AMPS @ 11 dBm
75
85
mA
Supply current in 800 MHz (driver on = off)
43
49
mA
Supply current in 1900 MHz CDMA @ 8 dBm
74
84
mA
Supply current in 1900 MHz CDMA @ 0 dBm
57
65
mA
Supply current in 1900 MHz CDMA (driver on = off)
42
48
mA
Supply current in sleep mode (chip enable = off, driver on = off)
20
A
Required LO Level
12
10
8
dBm
Note 1: The RF25F works at lower than 3.0 V VCC, but with some performance degradation.
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