
Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power
ECL prescaler
DESCRIPTION
The SA703 triple modulus (Divide By 128/129/144) low power ECL
prescaler is used in synthesizer systems to achieve low phase lock
time, broad operating range, high reference frequency and small
frequency step sizes. The minimum supply voltage is 2.7V and is
compatible with the UMA1005 synthesizer from Philips and other
logic circuits. The low supply current allows application in battery
operated low-power equipment. Maximum input signal frequency is
1.1GHz for cellular and other land mobile applications. There is no
lower frequency limit due to a fully static design. The circuit is
implemented in ECL technology on the QUBiC process. The circuit
will be available in an 8-pin SO package with 150 mil package width
and in 8-pin dual in-line plastic package.
APPLICATIONS
•Cellular phones
•Cordless phones
•RF LANs
•Test and measurement
•Military radio
PIN CONFIGURATION
•VHF/UHF mobile radio
•VHF/UHF hand-held radio
FEA TURES
•Low voltage operation
•Low current consumption
•Operation up to 1.1GHz
•ESD hardened
N, D Package
1
IN
2
V
CC
3
MC2
45
OUT
Figure 1. Pin Configuration
IN
8
7
GND
6
MC1
OUT
SA703
SR00551
ORDERING INFORMATION
DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #
8-Pin Plastic Dual In-Line Package (DIP)
8-Pin Plastic Small Outline (SO) package (Surface-mount)
-40 to +85°C
-40 to +85°C
SA703N SOT97-1
SA703D SOT96-1
ABSOLUTE MAXIMUM RATINGS
SYMBOL PARAMETER RATING UNITS
V
CC
V
IN
I
O
T
STG
T
A
θ
JA
Supply voltage -0.3 to +7.0 V
Voltage applied to any other pin -0.3 to (VCC + 0.3) V
Output current 10 mA
Storage temperature range -65 to +125 °C
Operating ambient temperature range -55 to +125 °C
Thermal impedance D package
N package
158
108
°C/W
1993 Jun 17 853-1710 10044
7–17

Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power ECL
prescaler
BLOCK DIAGRAM
OUT
SA703
OUT
Q
D
Q
D
QQ
D
QQ
D
Q
D
LOGIC
MODULUS CONTROL
Q
D
Q
D
Q
D
QQ
D
1993 Jun 17
IN
IN
MC1
MC2
SR00552
Figure 2. Block Diagram
7–18

Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power ECL
prescaler
DC ELECTRICAL CHARACTERISTICS
The following DC specifications are valid for TA = 25°C and VCC = 3.0V; unless otherwise stated. Test circuit Figure 4.
LIMITS
MIN TYP MAX
V
I
V
V
V
V
V
V
AC ELECTRICAL CHARACTERISTICS
These AC specifications are valid for VCC = 3.0V, fIN = 1GHz, input level = 0dBm, TA = 25°C; unless otherwise stated. Test circuit Fig. 4.
V
R
t
NOTES:
1. Maximum limit is not tested, however, it is guaranteed by design and characterization.
2. For f
DESCRIPTION OF OPERATION
The SA703 comprises a frequency divider circuit implemented using
a divide by 4 or 5 synchronous prescaler followed by a 5 stage
synchronous counter, see BLOCK DIAGRAM. The normal
operating mode is for MC1 (Modulus Control) to be set high and
MC2 input to be set low in which case the circuit comprises a divide
by 128. For divide by 129 the MC1 singal is forced low, causing the
prescaler circuit to switch into divide by 5 operation for the last cycle
of the synchronous counter. For divide by 144, MC2 is set high
configuring the prescaler to divide by 4 and the counter to divide by
36. A truth table for the modulus values is given in Table 1.
For minimization of propagation delay effects, the second divider
circuit is synchronous to the divide by 4/5 stage output.
The prescaler input is positive edge sensitive, and the output at the
final count is a falling edge with propagation delay t
Power supply voltage range fIN = 1GHz, input level = 0dBm 2.7 6.0 V
CC
Supply current No load 4.5 mA
CC
Output high level I
OH
Output low level VCC-2.6 V
OL
MC1 input high threshold 2.0 V
IH
MC1 input low threshold –0.3 0.8 V
IL
MC2 input high threshold 2.0 V
IH
MC2 input low threshold –0.3 0.8 V
IL
I
MC1 input high current V
IH
I
MC1 input low current V
IL
I
MC2 input high current V
IH
I
MC2 input low current V
IL
= 1.2mA VCC-1.4 V
OUT
= VCC = 6V 0.1 50 µA
MC1
= 0V, VCC = 6V –100 –30 µA
MC1
= VCC = 6V 0.1 50 µA
MC2
= 0V, VCC = 6V –100 –30 µA
MC2
LIMITS
MIN TYP MAX
Input signal amplitude
IN
nput signal frequency
Differential input resistance DC measurement 5 kΩ
ID
voltage
t
Modulus set-up time
S
t
Modulus hold time
H
Propagation time 10 ns
PD
< 50MHz, minimum input slew rate of 32V/µs is required.
IN
1
1000pF input coupling 0.05 2.0 V
Direct coupled input
2
0 1.1
1000pF input coupling 1.1
VCC = 5.0V 1.6
VCC = 3.0V 1.2
1
1
input. The rising edge of the output occurs at the count 64 with
PD
.
delay t
The MC1 and MC2 inputs are TTL compatible threshold inputs
operating at a reduced input current. CMOS and low voltage
interface capability are allowed.
The prescaler input is differential and ECL compatible. The output is
differential ECL compatible.
Table 1.
Modulus MC1 MC2
128 1 0
129 0 0
144 0 1
relative to the
PD
144 1 1
SA703
CC
CC
5 ns
0 ns
V
V
P-P
z
P-P
1993 Jun 17
7–19

Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power ECL
prescaler
AC TIMING CHARACTERISTICS
128 129 1 64 127 128 1COUNT
IN
MC (2:1)
OUT
OUT
(00) (XX) (01)
t
PD
128 129 1 64 143 144 1COUNT
IN
SWITCH FROM /129 TO /128
126 127 128
SA703
t
S
t
H
MC
OUT
(00) (XX) (10)
t
t
PD
SWITCH FROM /129 TO /144
S
Figure 3. AC Timing Characteristics
t
H
SR00553
1993 Jun 17
7–20

Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power ECL
prescaler
IN IN
50Ω 50Ω
V
MC2
R1
CC
C3
0.1µF
C1
1000pF
IN
V
CC
MC2
OUT OUT
IN
GND
MC1
C2
1000pF50Ω
2.2kΩ
SA703
R2
50Ω
MC1
OUT
R4
C5
5pF
0
–5
–10
–15
–20
–25
MINIMUM INPUT POWER (dBm)
–30
–35
200 400 600 800 1000 1200
R3
2.2kΩ
C4
5pF
Figure 4. SA703 Test Circuit
FREQUENCY (MHz)
OUT
SR00554
–40°C
V
CC
= 3.0V
25°C
85°C
1993 Jun 17
–40
SR00555
Figure 5. Minimum Input Power vs Frequency and Temperature
7–21

Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power ECL
prescaler
0
–5
–10
–15
–20
–25
–30
MINIMUM INPUT POWER (dBm)
–35
–40
200 400 600 800 1000 1200
Figure 6. Minimum Input Power vs Frequency and V
6
FREQUENCY (MHz)
TA = 25°C
SA703
2.7V
3.0V
6.0V
SR00556
CC
85°C
5.5
5
4.5
CC
I (mA)
4
3.5
3
2.7 3 6 7
VCC (V)
25°C
–40°C
Figure 7. Supply Current vs Supply Voltage and Temperature With No Load
SR00557
1993 Jun 17
7–22

Philips Semiconductors Product specification
Divide by: 128/129/144 triple modulus low power ECL
prescaler
j1
j0.2
0
–j0.2
j0.5
0.2 0.5 1 2
900
j2
600
5
300
j5
INPUT
50
–j5
VCC = 3V
= 25°C
T
A
L4
R3
6nH
4Ω
C2 C1
0.4pF
EQUIVALENT INPUT IMPEDANCE
R1
3000Ω
SA703
0.9pF
j0.2
0
–j0.2
–j0.5
–j1
Figure 8. Typical N Package Input Impedance
j1
j0.5
0.2 0.5 1 2
1200
900
j2
600
–j2
5
300
SR00558
V
j5
INPUT
50
–j5
= 3V
CC
= 25°C
T
A
L4
R3
3nH
2Ω
C2 C1
0.2pF
EQUIVALENT INPUT IMPEDANCE
3000Ω
R1
0.9pF
1993 Jun 17
–j0.5
1200
–j1
–j2
Figure 9. Typical D Package Input Impedance
7–23
SR00559