SA5214 Datasheet, PDF (7/10 Pages) NXP Semiconductors – Postamplifier with link status indicator

Philips Semiconductors
Postamplifier with link status indicator
Product specification
SA5214
+V_CC
47µF
C1
C2
.01µF
GND
R2
D1
220
LED
C9
100pF
L2
10µH
C10
10µF
R3
47k
C11
.01µF
L3
10µH
C12
10µF
C13
.01µF
1 ^LED
2 ^CPKDET
3 ^THRESH
4 ^GNDA
5 ^FLAG
6 ^JAM
7 ^VCCD
8 ^VCCA
9 ^GNDD
10 TTLOUT
V_OUT (TTL)
C7
IN_1B 20
IN_1A ¹⁹
C_AZP ¹⁸
100pF
C8
C_AZN ¹⁷ _0.1µF
OUT_1B ¹⁶
IN_2B ¹⁵
OUT_1A ¹⁴
IN_2A ¹³
R_HYST ¹²
R_{PKDET 11}
R4
5.1k
8 GND
9 _GND
10 ^GND
11 ^GND
12 OUT
13 GND
14 OUT
V_CC 7
V_CC 6
NC 5
I_IN 4
NC ₃
GND 2
GND ₁
L1
10µH
R1
100
C5
1.0µF
C4
.01µF
C3
10µF
.01µF
C6
BPF31
OPTICAL
INPUT
NOTE:
The NE5211/NE5214 combination can operate at data rates in excess of 100Mb/s NRZ.
Figure 5. A 50Mb/s Fiber Optic Receiver
SD00353
THEORY OF OPERATION AND APPLICATION
INFORMATION
The SA5214 postamplifier system is a highly integrated chip that
provides up to 60dB of gain at 60MHz, to bring mV level signals up
to TTL levels.
The SA5214 contains eight amplifier blocks (see Block Diagram).
The main signal path is made up of a cascade of limiting stages: A1,
A2 and A8. The A3-A4-A7 path performs a wideband full-wave
rectification of the input signal with adjustable hysteresis and decay
times. It outputs a TTL HIGH on the “FLAG” output (Pin 5) when the
input is below a user adjustable threshold. An on-chip LED driver
turns the external LED to the ON state when the input signal is
above the threshold. In a typical application the “FLAG” output is tied
back to the “JAM” input; this forces the TTL data OUT into a LOW
state when no signal is present at the input.
An auto zero loop allows the SA5214 to be directly connected to a
transimpedance amplifier such as the SA5210, SA5211, or SA5212
without coupling capacitors. This auto-zero loop cancels the
transimpedance amplifier’s DC offset, the SA5214 A1 offset, and the
data-dependent offset in the PIN diode/transimpedance amplifier
combination. For more information on the SA5214 Theory of
Operation, please refer to paper titled “A Low Cost 100 MBaud
Fiber-Optic Receiver” by W. Mack et al.
A typical application of the SA5214 postamplifier is depicted in
Figure 5. The system uses the SA5211 transimpedance amplifier
which has a 28k differential transimpedance gain and a -3dB
bandwidth of 140MHz. This typical application is optimized for a 50
Mb/s Non Return to Zero (NRZ) bit stream.
As the system’s gain bandwidth product is very high, it is crucial to
employ good RF design and printed circuit board layout techniques
to prevent the system from becoming unstable.
For more information on this application, please refer to AB 1432.
Die Sales Disclaimer
Due to the limitations in testing high frequency and other parameters
at the die level, and the fact that die electrical characteristics may
shift after packaging, die electrical parameters are not specified and
die are not guaranteed to meet electrical characteristics (including
temperature range) as noted in this data sheet which is intended
only to specify electrical characteristics for a packaged device.
1998 Oct 07
7