INTEGRATED CIRCUITS
DATA SHEET
SAB6456
SAB6456T
Sensitive 1 GHz
divide-by-64/divide-by-256
switchable prescaler
Product specification
File under Integrated Circuits, IC02
June 1986
Philips Semiconductors
Product specification
Sensitive 1 GHz divide-by-64/divide-by-256
switchable prescaler
GENERAL DESCRIPTION
SAB6456
SAB6456T
The SAB6456/SAB6456T is a prescaler for UHF/VHF tuners. It can be switched to divide-by-64 or divide-by-256 by the
mode-control (MC) pin. The circuit has an input frequency range of 70 MHz to 1 GHz, has high input sensitivity and good
harmonic suppression.
Fig.1 Block diagram.
QUICK REFERENCE DATA
PARAMETER
Supply voltage
Supply current
Input frequency range
Sensitivity to input voltage
(r.m.s. value)
Output voltage
(peak-to-peak value)
Operating ambient
temperature range
PACKAGE OUTLINES
SAB6456 : 8-lead DIL; plastic (SOT97); SOT97-1; 1996 November 18.
SAB6456T: 8-lead mini-pack (SO8; SOT96A); SOT96-1; 1996 November 18.
T
amb
0
−
80
°C
pins 6 and 7
V
o(p-p)
−
1
−
V
V
i(rms)
−
−
10
mV
CONDITIONS
pin 8 to pin 4
pin 8
pins 2 and 3
SYMBOL
V
CC
I
CC
f
i
−
70
MIN.
4,5
TYP.
5,0
21
−
−
1000
MAX.
5,5
V
mA
MHz
UNIT
June 1986
2
Philips Semiconductors
Product specification
Sensitive 1 GHz divide-by-64/divide-by-256
switchable prescaler
PINNING
1.
2.
3.
4.
5.
6.
7.
8.
Fig.2 Pinning diagram.
n.c.
C1
C2
V
EE
MC
Q
H
Q
L
V
CC
not connected
SAB6456
SAB6456T
differential inputs
ground (0 V)
mode control
complementary outputs
positive supply voltage
FUNCTIONAL DESCRIPTION
The circuit comprises an input amplifier, a divider stage with selectable division ratio and an output stage.
The input amplifier is driven by a sinusoidal signal from the local oscillator of a television tuner. The inputs (C1, C2) are
differential and are biased internally to permit capacitive coupling. When driven asymmetrically the unused input should
be connected to ground via a capacitor.
The mode-control (MC) input to the divider stage is intended for static control of the division ratio, selection is made as
follows:
divide-by-64: MC pin open-circuit
divide-by-256: MC pin connected to ground
The divider stage may oscillate during no-signal conditions but this oscillation is suppressed when input signals are
received.
Two complementary signals (Q
H
, Q
L
) are provided by the output differential amplifier stage. The voltage-edges of the
output signals are slowed internally to reduce harmonics in the television intermediate frequency band.
June 1986
3
Philips Semiconductors
Product specification
Sensitive 1 GHz divide-by-64/divide-by-256
switchable prescaler
ELECTROSTATIC DISCHARGE PROTECTION
SAB6456
SAB6456T
Inputs and outputs have electrostatic discharge protection according to specification MIL-883C, class B.
RATINGS
Limiting values in accordance with the Absolute Maximum System (IEC-134)
PARAMETER
Supply voltage
Input voltage
Storage temperature range
Junction temperature
THERMAL RESISTANCE
From junction to ambient
8-lead DIL; plastic (SOT-97A)
8-lead mini-pack (SO-8; SOT-96A)
on printed circuit board
on ceramic substrate
R
th j-a
R
th j-a
260 K/W
170 K/W
R
th j-a
120 K/W
CONDITIONS
pin 8 to pin 4
SYMBOL
V
CC
V
i
T
stg
T
j
−
−
−55
−
MIN.
−
−
−
−
TYP.
MAX.
7,0
V
CC
+
150
+
150
V
V
°
C
°
C
UNIT
D.C. CHARACTERISTICS
V
CC
= 5 V; V
EE
= 0 V; T
amb
= 25
°C;
test IC mounted in a test socket or on a printed circuit board; measurements taken
after thermal equilibrium is established
PARAMETER
Output voltage HIGH
Output voltage LOW
Supply current
Mode-control (MC)
Input voltage LOW
(divide-by-256)
Input current LOW
Input voltage HIGH
(divide-by-64)
pin 5 open-circuit
V
IH
1,4
−
3,0
V
V
IL
−I
L
0
−
−
25
0,2
60
V
µA
CONDITIONS
V
OH
V
OL
I
CC
SYMBOL
−
−
−
MIN.
TYP.
−
−
21
MAX.
V
CC
V
CC
−
0.8
28
UNIT
V
V
mA
June 1986
4
Philips Semiconductors
Product specification
Sensitive 1 GHz divide-by-64/divide-by-256
switchable prescaler
A.C. CHARACTERISTICS
V
CC
= 4,5 to 5,5 V; V
EE
= 0 V; T
amb
= 0 to
+80 °C
PARAMETER
Sensitivity to input
voltage (r.m.s. value)
CONDITIONS
50
Ω
system
f
i
=
70 MHz
V
i(rms)
V
i(rms)
V
i(rms)
V
i(rms)
V
i(rms)
V
i(rms)
−
−
−
−
−
−
−
−
−
−
−
−
10
10
10
10
10
10
SYMBOL
MIN.
TYP.
SAB6456
SAB6456T
MAX.
UNIT
mV
mV
mV
mV
mV
mV
f
i
= 150 MHz
f
i
= 300 MHz
f
i
= 500 MHz
f
i
= 900 MHz
f
i
= 1000 MHz
Input overload voltage
(r.m.s. value)
Input parallel resistance
Input capacitance
Output voltage HIGH
Output voltage LOW
Output voltage swing
(peak-to-peak value)
f
i
=
70 MHz
50
Ω
system
f
i
= 70 MHz to
1000 MHz
f
i
=
f
i
=
70 MHz
70 MHz
f
i
= 1000 MHz
f
i
= 1000 MHz
V
i
R
i
R
i
C
i
C
i
V
OH
V
OL
300
−
−
−
−
−
−
−
560
30
5
1,5
−
−
−
−
−
−
−
V
CC
V
CC
−
0,8
mV
Ω
Ω
pF
pF
V
V
V
o(p-p)
0,8
1,0
1,2
V
f
i
= 1000 MHz;
R
L
= 820
Ω;
C
L
= 60 pF
Attenuation of third
harmonic at output
f
i
= 800 MHz;
R
L
= 820
Ω;
C
L
= 60 pF
Output unbalance
Output resistance
see Fig.3
∆V
o
R
o
−15
−
−
−23
−
500
−
0,1
−
dB
V
Ω
V
o(p-p)
0,17
−
−
V
June 1986
5
微控制器 MCU
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
