Philips Semiconductors
Photodetector amplifiers and laser
supplies
Preliminary specification
TDA1300T; TDA1300TT
Transfer functions; see Fig.6
The equalized amplifier including Cext and Rext has the following transfer functions, where ‘RFE’ refers to equalized
output only and ‘RF’ refers to equalized and not equalized outputs.
FOR SINGLE SPEED (SP = LOGIC 1)
I--i-V(--c--eR---n-F-t-r-E-a--l-) = RRF × 1-----+-----1-----⁄---Q--1----×-–----sk----s⁄---ω2----o---s⁄---ω-+---2--s-o--2-s---⁄--ω-----2--o---s- × -1----+-----s-1----⁄--ω-----1 × 1-----+-----s----R----e--1-x---t---×----C-----e---x--t
(1)
FOR DOUBLE SPEED (SP = LOGIC 0)
I--i-V(--c--eR---n-F-t-r-E-a--l-) = RRF × -1----+-----1-----⁄---Q--1----×-–----sk----s⁄---ω2----o---d⁄---ω-+---2--s-o--2-s---⁄---ω----2---o---d × -1----+-----s----R----e--1-x---t---×----C-----e---x--t
(2)
The denominator forms the denominator of a Bessel low-pass filter.
Symbols used in equations (1) and (2) are explained in Table 3.
Table 3 Transresistance
SYMBOL
k
ωos/ω1
Q
ωod = 2 × ωos
RRF
Rext
Cext
DESCRIPTION
internally defined
internally defined
internally defined
internally defined
see Chapter “Characteristics”
external resistor
external capacitor
TYP.
4
1.094
0.691
17.6 × 10−6
−
750
47
UNIT
rad/s
Ω
pF
1997 Jul 15
10