Philips Semiconductors
Product specification
Voltage reference diodes
ELECTRICAL CHARACTERISTICS
T
j
= 25
°C
unless otherwise specified.
SYMBOL
V
ref
∆V
ref
PARAMETER
reference voltage
reference voltage excursion
1N821; 1N821A
1N823; 1N823A
1N825; 1N825A
1N827; 1N827A
1N829; 1N829A
S
Z
temperature coefficient
1N821; 1N821A
1N823; 1N823A
1N825; 1N825A
1N827; 1N827A
1N829; 1N829A
r
dif
differential resistance
1N821 to 1N829
1N821A to 1N829A
Notes
I
Z
= 7.5 mA; see Fig.4
−
−
I
Z
= 7.5 mA: see Fig.3;
notes 1 and 2
CONDITIONS
I
Z
=7.5 mA
I
Z
=7.5 mA; test points for
T
amb
:
−55;
+25; +75; +100
°C;
see Fig.2; notes 1 and 2
MIN.
5.89
−
−
−
−
−
−
−
−
−
−
1N821 to 1N829
1N821A to 1N829A
TYP.
6.20
−
−
−
−
−
−
−
−
−
−
−
−
MAX.
6.51
96
48
19
9
5
0.01
0.005
0.002
0.001
V
UNIT
mV
mV
mV
mV
mV
%/K
%/K
%/K
%/K
0.0005 %/K
15
10
Ω
Ω
1. The quoted values of
∆V
ref
are based on a constant current I
Z
. Two factors can cause
∆V
ref
to change, namely the
differential resistance r
dif
and the temperature coefficient S
Z
.
a) As the max. r
dif
of the device can be 15
Ω,
a change of 0.01 mA in the current through the reference diode will
result in a
∆V
ref
of 0.01 mA
×
15
Ω
= 0.15 mV. This level of
∆V
ref
is not significant on a 1N821 (∆V
ref
< 96 mV),
it is however very significant on a 1N829 (∆V
ref
< 5 mV).
b) The temperature coefficient of the reference voltage S
Z
is a function of I
Z
. Reference diodes are classified at the
specified test current and the S
Z
of the reference diode will be different at different levels of I
Z
. The absolute value
of I
Z
is important, however, the stability of I
Z
, once the level has been set, is far more significant. This applies
particularly to the 1N829. The effect of the stability of I
Z
on S
Z
is shown in Fig.3.
2. All reference diodes are characterized by the ‘box method’. This guarantees a maximum voltage excursion (∆V
ref
)
over the specified temperature range, at the specified test current (I
Z
), verified by tests at indicated temperature
points within the range. V
Z
is measured and recorded at each temperature specified. The
∆V
ref
between the highest
and lowest values must not exceed the maximum
∆V
ref
given. Therefore the temperature coefficient is only given as
V
ref1
–
V
ref2
100
a reference. It may be derived from: S
Z
=
-------------------------------------
×
------------------- %/K
-
-
T
amb2
–
T
amb1
V
ref nom
THERMAL CHARACTERISTICS
SYMBOL
R
th j-tp
R
th j-a
PARAMETER
thermal resistance from junction to tie-point
thermal resistance from junction to ambient
CONDITIONS
8 mm from the body
lead length 10 mm
VALUE
300
375
UNIT
K/W
K/W
1996 Mar 20
3
PHILIPS [ NXP SEMICONDUCTORS ]
