FOD2712R1 Datasheet, PDF (4/16 Pages) Fairchild Semiconductor – Optically Isolated Error Amplifier

Electrical Characteristics (V_CC = 12V, T_A = 25°C unless otherwise specified)
Input Characteristics
Symbol
Parameter
Test Conditions
Min. Typ. Max. Unit
V_F
LED Forward Voltage
I_LED = 10mA, V_COMP = V_FB
(Fig.1)
1.5 V
V_REF
Reference Voltage
-40°C to +85°C
25°C
V_COMP = V_FB, I_LED = 10mA
(Fig.1)
1.221
1.259 V
1.228 1.240 1.252
V_{REF (DEV)} Deviation of V_REF over temperature
See Note 1
T_A = -40 to +85°C
4
12 mV
∆V_REF
∆V_COMP
Ratio of Vref Variation to the Output of the I_LED = 10 mA,
Error Amplifier
V_COMP = V_REF to 12V
(Fig. 2)
-1.5 -2.7 mV/V
I_REF Feedback Input Current
I_LED = 10mA, R1 = 10kΩ
(Fig. 3)
0.15 0.5 µA
I_{REF (DEV)} Deviation of I_REF Over Temperature
See Note 1
T_A = -40 to +85°C
0.15 0.3 µA
I_{LED (MIN)}
I_(OFF)
|Z_OUT|
Minimum Drive Current
Off-state Error Amplifier Current
Error Amplifier Output Impedance
See Note 2
V_COMP = V_FB (Fig.1)
V_LED = 6V, V_FB = 0 (Fig.4)
V_COMP = V_FB,
I_LED = 0.1mA to 15mA,
f < 1kHZ
55 80 µA
0.001 0.1 µA
0.25
Ω
Notes:
1. The deviation parameters V_REF(DEV) and I_REF(DEV) are defined as the differences between the maximum and
minimum values obtained over the rated temperature range. The average full-range temperature coefficient of the
reference input voltage, ∆V_REF, is defined as:
∆V_REF (ppm/°C)
=
{_{----V----R----E---F---(--D----E----V---)--/--V----R----E---F----}(_{--T----A-----=------2---5----°--C-----})_--}_-----×_{----1----0---}⁶_-
∆T_A
where ∆T_A is the rated operating free-air temperature range of the device.
2. The dynamic impedance is defined as |Z_OUT| = ∆V_COMP/∆I_LED. When the device is operating with two external
resistors (see Figure 2), the total dynamic impedance of the circuit is given by:
Z_{OUT, TOT} = ^∆--_∆---V-I- ≈ Z_OUT ×
1 + ^R-----1--
R2
©2003 Fairchild Semiconductor Corporation
FOD2712 Rev. 1.0.1
4
www.fairchildsemi.com