Audio, Dual-Matched
NPN Transistor
Data Sheet
SSM2212
Rev. C Document Feedback
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FEATURES
Very low voltage noise: 1 nV/√Hz maximum at 100 Hz
Excellent current gain match: 0.5%
Low offset voltage (V
OS
): 200 μV maximum (SOIC)
Outstanding offset voltage drift: 0.03 μV/°C
High gain bandwidth product: 200 MHz
PIN CONNECTIONS
C
1
1
B
1
2
E
1
3
NIC
4
C
2
8
B
2
7
E
2
6
NIC
5
SSM2212
09043-001
NOTES
1. NIC = NO INTERNAL CONNECTION.
Figure 1. 8-Lead SOIC_N
09043-020
12
11
10
1
3
4
9
2
6
5
7
8
16
15
14
13
SSM2212
E
1A
E
1B
E
2B
E
2A
NIC
C
1
NIC
B
1
NIC
C
2
NIC
NIC
NIC
B
2
NIC
NIC
NOTES
1. NIC = NO INTERNAL CONNECTION.
Figure 2. 16-Lead LFCSP_WQ
GENERAL DESCRIPTION
The SSM2212 is a dual, NPN-matched transistor pair that is
specifically designed to meet the requirements of ultralow noise
audio systems.
With its extremely low input base spreading resistance (rbb' is
typically 28 Ω) and high current gain (h
FE
typically exceeds 600 at
I
C
= 1 mA), the SSM2212 can achieve outstanding signal-to-noise
ratios. The high current gain results in superior performance
compared to systems incorporating commercially available
monolithic amplifiers.
Excellent matching of the current gain (Δh
FE
) to approximately
0.5% and low V
OS
of less than 10 μV typical make the SSM2212
ideal for symmetrically balanced designs, which reduce high-
order amplifier harmonic distortion.
Stability of the matching parameters is guaranteed by protection
diodes across the base-emitter junction. These diodes prevent
degradation of beta and matching characteristics due to reverse
biasing of the base-emitter junction.
The SSM2212 is also an ideal choice for accurate and reliable
current biasing and mirroring circuits. Furthermore, because
the accuracy of a current mirror degrades exponentially with
mismatches of V
BE
between transistor pairs, the low V
OS
of the
SSM2212 does not need offset trimming in most circuit
applications.
The SSM2212 SOIC performance and characteristics are
guaranteed over the extended temperature range of −40°C to
+85°C.
The SSM2212 is available in 8-lead SOIC and 16-lead LFCSP
packages.
