參數(shù)資料
型號: MAT02AH/883C
廠商: ANALOG DEVICES INC
元件分類: 小信號晶體管
英文描述: 20 mA, 40 V, 2 CHANNEL, NPN, Si, SMALL SIGNAL TRANSISTOR, TO-78
封裝: TO-78, 6 PIN
文件頁數(shù): 10/12頁
文件大?。?/td> 264K
代理商: MAT02AH/883C
MAT02
–7–
REV. C
Figure 18. Log Conformance Test Circuit
LOG CONFORMANCE TESTING
The log conformance of the MAT02 is tested using the circuit
shown above. The circuit employs a dual transdiode logarith-
mic converter operating at a fixed ratio of collector currents
that are swept over a 10:1 range. The output of each transdiode
converter is the VBE of the transistor plus an error term which
is the product of the collector current and rBE, the bulk emitter
resistance. The difference of the VBE is amplified at a gain of
×100 by the AMP01 instrumentation amplifier. The differen-
tial emitter-base voltage (
V
BE) consists of a temperature-
dependent dc level plus an ac error voltage which is the devia-
tion from true log conformity as the collector currents vary.
The output of the transdiode logarithmic converter comes
from the idealized intrinsic transistor equation (for silicon):
VBE =
kT
q
In
IC
IS
where
(1)
k = Boltzmann’s Constant (1.38062
× 10-23 J/°K)
q = Unit Electron Charge (1.60219
× 10-19 °C)
T = Absolute Temperature,
°K (= °C + 273.2)
IS = Extrapolated Current for VBE→0
IC = Collector Current
An error term must be added to this equation to allow for the
bulk resistance (rBE) of the transistor. Error due to the op amp
input current is limited by use of the OP15 BiFET-input op
amp. The resulting AMP01 input is:
V
BE =
kT
q
In
IC1
IC2
+ IC1 rBE1 – IC2 rBE2
(2)
A ramp function which sweeps from 1 V to 10 V is converted by
the op amps to a collector current ramp through each transistor.
Because IC1 is made equal to 10 IC2, and assuming TA = 25°C,
the previous equation becomes:
V
BE = 59 mV + 0.9 IC1 rBE (
r
BE ~ 0)
As viewed on an oscilloscope, the change in
V
BE for a 10:1
change in IC is then displayed as shown below:
相關(guān)PDF資料
PDF描述
MAT02AH/883 20 mA, 40 V, 2 CHANNEL, NPN, Si, SMALL SIGNAL TRANSISTOR, TO-78
MAT-02AH/883 20 mA, 40 V, 2 CHANNEL, NPN, Si, SMALL SIGNAL TRANSISTOR, TO-78
MAT-02AH 20 mA, 40 V, 2 CHANNEL, NPN, Si, SMALL SIGNAL TRANSISTOR, TO-78
MAT02BRC/883 20 mA, 40 V, 2 CHANNEL, NPN, Si, SMALL SIGNAL TRANSISTOR
MAT02AH/883 20 mA, 40 V, 2 CHANNEL, NPN, Si, SMALL SIGNAL TRANSISTOR, TO-78
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAT02BH 制造商:Rochester Electronics LLC 功能描述:- Bulk
MAT02BH/883C 制造商:Rochester Electronics LLC 功能描述:- Bulk
MAT02BIEH 制造商:Rochester Electronics LLC 功能描述:- Bulk
MAT02BRC/883C 制造商:Rochester Electronics LLC 功能描述:- Bulk
MAT02EH 制造商:Analog Devices 功能描述:AMPLIFIER IC NUMBER OF CIRCUITS:2