TK14588 TOKO, TK14588 Datasheet - Page 17

• Manufacturer Part Number: TK14588
• Description: FM IF IC
• Manufacturer: TOKO

CIRCUIT DESCRIPTION (CONT.)
Comparator:
The TK14588V contains a general purpose high-speed data comparator for the base band processing. Because the input
stage is composed of PNP transistors, it is possible to operate from a minimum voltage of 0.2 V to the supply voltage minus
0.9 V (see Figure 10).
Moreover, as the HFE of this PNP transistor is over 100, the bias current is below 0.01 A (this is below 10% of the value
of the general products on the market using lateral PNP transistor at input stage).
January 2000 TOKO, Inc.
FIGURE 9 - EXAMPLE OF DIVIDING SUPPLY VOLTAGE INTO HALVES BY THE RESISTORS
Output Current
Demodulated
FIGURE 8 - EXAMPLE OF USING EXTERNAL REFERENCE SOURCE
R2
VB
R1
R1 = R2
io
V CC
R1
C1
V ref
FIGURE 10 - COMPARATOR INPUT STAGE
C1
Output Voltage
Demodulated
I to V convertor
Output Voltage
V OUT
Demodulated
V OUT
INPUT STAGE
Demodulated Output Voltage V
Demodulated Bandwidth
1/gm is about 50 k that is the output resistance of the
multiplier.
Pin 11 is disconnected.
Demodulated Output Voltage V
Demodulated Bandwidth
1/gm is about 50 k that is the output resistance of the
multiplier.
Pin 11 is disconnected.
Fc =
Fc =
OUT
OUT
= V
= VB
2
2
CC
C1(1/gm)
C1(1/gm)
/2
TK14588
1
1
R1 x io
R1 x io
Page 17