8178
LOW-DROPOUT,
7.7 V PREREGULATOR
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
ELECTRICAL CHARACTERISTICS over operating temperature range.
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Output Voltage VO6.9 V ≤ VI ≤ 24 V 6.5 7.7 8.8 V
2.5 V ≤ VI ≤ 6.9 V VI - 0.4 — — V
VI = 120 V, pulse test — — 11 V
Output Volt. Temp. Coeff. αVO — — TBD mV/°C
Line Regulation ∆VO(∆VI) — — TBD mV
Load Regulation ∆VO(∆IO) — — TBD mV
Quiescent Current IQVI = 13.5 V, IO = 0 — — 2.5 mA
2.5 V ≤ VI ≤ 8 V, IO = 0 — — 5.6 mA
Power Dissipation PdVI = 13.5 V, IO = 15 mA — — 130 mW
Thermal Resistance* RθJA A8178LLR — 575 — °C/W
A8178LLT — 200 — °C/W
Typical values are at TA = +25°C and are given for circuit design information only.
*Mounted on 2.24" x 2.24" solder-coated copper-clad board in still air.
INTERNAL PROTECTIVE FEATURES
ISO
Pulse No. Test Test Conditions (at TA = +25°C)
1 Inductive Turn Off (Negative) VS = -100 V, RS = 10 Ω, tr = 1 µs, t d = 2 ms
2 Inductive Turn Off (Positive) VS = 100 V, RS = 10 Ω, tr = 1 µs, td = 50 µs, non-operating
3a Capacitive/Inductive Coupling (Neg) VS = -150 V, RS = 50 Ω, tr = 50 ns, td = 100 ns
3b Capacitive/Inductive Coupling (Pos) VS = 100 V, RS = 50 Ω, tr = 50 ns, td = 100 ns
4 Reverse Battery VS = -14 V, td = 20 s, non-operating
5 Load Dump VS = 86.5 V, RS = 0.5 Ω, tr = 5 ms, td = 400 ms
6 Ignition Coil Disconnect VS = -300 V, RS = 30 Ω, tr = 60 µs, t d = 300 µs
EXTERNAL PROTECTION REQ’D
7 Field Decay (Negative) VS = -80 V, RS = 10 Ω, tr = 5 ms, td = 100 ms
Copyright © 1996 Allegro MicroSystems, Inc.