Philips Semiconductors RF Communications Products Product specification
SA702
Divide by: 64/65/72 triple modulus low power
ECL prescaler
June 17, 1993
4
DC ELECTRICAL CHARACTERISTICS
The following DC specifications are valid for TA = 25°C and VCC = 3.0V; unless otherwise stated. Test circuit Figure 1.
SYMBOL
PARAMETER TEST CONDITIONS LIMITS UNITS
MIN TYP MAX
V
CC
Power supply voltage range fIN = 1GHz, input level = 0dBm 2.7 6.0 V
I
CC
Supply current No load 4.5 mA
V
OH
Output high level I
OUT
= 1.2mA VCC-1.4 V
V
OL
Output low level VCC-2.6 V
V
IH
MC1 input high threshold 2.0 V
CC
V
V
IL
MC1 input low threshold –0.3 0.8 V
V
IH
MC2 input high threshold 2.0 V
CC
V
V
IL
MC2 input low threshold –0.3 0.8 V
I
IH
MC1 input high current V
MC1
= VCC = 6V 0.1 50 µA
I
IL
MC1 input low current V
MC1
= 0V, VCC = 6V –100 –30 µA
I
IH
MC2 input high current V
MC2
= VCC = 6V 0.1 50 µA
I
IL
MC2 input low current V
MC2
= 0V, VCC = 6V –100 –30 µA
AC ELECTRICAL CHARACTERISTICS
These AC specifications are valid for fIN = 1GHz, input level = 0dBm, VCC = 3.0V and TA = 25°C; unless otherwise stated. Test circuit Fig. 1.
SYMBOL
PARAMETER TEST CONDITIONS LIMITS UNITS
MIN TYP MAX
V
IN
Input signal amplitude
1
1000pF input coupling 0.05 2.0 V
P-P
f
IN
Input signal frequency Direct coupled input
2
0 1.1 GHz
1000pF input coupling 1.1 GHz
R
ID
Differential input resistance DC measurement 5 kΩ
V
O
Output voltage VCC = 5.0V 1.6 V
P-P
VCC = 3.0V 1.2 V
P-P
t
S
Modulus set-up time
1
5 ns
t
H
Modulus hold time
1
0 ns
t
PD
Propagation time 10 ns
NOTES:
1. Maximum limit is not tested, however, it is guaranteed by design and characterization.
2. For f
IN
< 50MHz, minimum input slew rate of 32V/µs is required.
DESCRIPTION OF OPERATION
The SA702 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 64. For divide
by 65 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 72, MC2
is set high configuring the prescaler to divide
by 4 and the counter to divide by 18. A truth
table for the modulus values is given below:
Table 1.
Modulus MC1 MC2
64 1 0
65 0 0
72 0 1
72 1 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
PD
relative to
the input. The rising edge of the output
occurs at the count 32 with delay t
PD
.
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.