Philips Semiconductors
SA5211
Transimpedance amplifier (180 MHz)
strongly determined by the quiescent current of Q1, the feedback resistor RF, and the
bandwidth; however, it is not dependent upon the internal Miller-capacitance. The
measured wideband noise was 41 nA RMS in a 200 MHz bandwidth.
14. Dynamic range calculations
The electrical dynamic range can be defined as the ratio of maximum input current to
the peak noise current:
Electrical dynamic range, DE, in a 200 MHz bandwidth assuming IINMAX = 60 µA and
a wideband noise of IEQ = 41 nARMS for an external source capacitance of CS = 1 pF.
DE = (-(--MP---e--a-a--xk---.--n-i-n-o--p-i--su--e-t---cc---uu---rr--rr--ee---nn---tt-)-)
(5)
DE (dB) = 20 log(-(--6---20-----4×--1---1-1--0-0--–-–-6-9--)-)
(6)
DE(dB) = 20 log (-(--65---08-----µn----AA----)-)= 60db
(7)
In order to calculate the optical dynamic range the incident optical power must be
considered.
For a given wavelength λ;
Energy of one Photon = h--λ--c- watt sec (Joule)
Where h = Planck’s Constant = 6.6 × 10-34 Joule sec.
c = speed of light = 3 × 108 m/sec
c / λ = optical frequency
--P---
No. of incident photons/sec = -h-λ--c- where P = optical incident power
--P---
No. of generated electrons/sec = η × -h-λ--c-
where η = quantum efficiency
=
n----o---.---o---f---g---e---n---e--r--a---t--e--d-----e---l-e---c---t-r--o---n-----h---o---l--e----p---a--i--r--s-
no. of incident photons
9397 750 07427
Product specification
Rev. 03 — 07 October 1998
© Philips Electronics N.V. 2001. All rights reserved.
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