Audio Dual Matched PNP Transistor
Data Sheet
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FEATURES
Low voltage noise at 100 Hz, 1 nV/√Hz maximum
High gain bandwidth: 190 MHz typical
Gain at I
C
= 1 mA, 165 typical
Tight gain matching: 3% maximum
Outstanding logarithmic conformance: r
BE
= 0.3 Ω typical
Low offset voltage: 200 μV maximum
APPLICATIONS
Microphone preamplifiers
Tape head preamplifiers
Current sources and mirrors
Low noise precision instrumentation
Voltage controlled amplifiers/multipliers
PIN CONNECTION DIAGRAM
C
1
1
B
1
2
E
1
3
NC
4
C
2
8
B
2
7
E
2
6
NC
5
SSM2220
TOP VIEW
(Not to Scale)
03096-001
NOTES
1. NC = NO CONNECT. THIS PIN IS
NOT CONNECTED INTERNALLY.
Figure 1.
GENERAL DESCRIPTION
The SSM2220 is a dual, low noise, matched PNP transistor, which
has been optimized for use in audio applications.
The ultralow input voltage noise of the SSM2220 is typically only
0.7 nV/√Hz over the entire audio bandwidth of 20 Hz to 20 kHz.
The low noise, high bandwidth (190 MHz), and offset voltage of
(200 μV maximum) make the SSM2220 an ideal choice for demand
ing, low noise preamplifier applications.
The SSM2220 also offers excellent matching of the current gain
(Δh
FE
) to about 0.5%, which helps to reduce the high order ampli-
fier harmonic distortion. In addition, to ensure the long-term
stability of the matching parameters, internal protection diodes
across the base to emitter junction were used to clamp any reverse
base to emitter junction potential. This prevents a base to emitter
breakdown condition, which can result in degradation of gain and
matching performance due to excessive breakdown current.
Another feature of the SSM2220 is its very low bulk resistance
of 0.3 Ω typical, which assures accurate logarithmic conformance.
The SSM2220 is offered in 8-lead plastic dual inline (PDIP) and
8-lead standard small outline (SOIC), and its performance and
characteristics are guaranteed over the extended industrial temper-
ature range of −40°C to +85°C.
