LM3411AM5-5.0/NOPB National Semiconductor, LM3411AM5-5.0/NOPB Datasheet - Page 9

• Manufacturer Part Number: LM3411AM5-5.0/NOPB
• Description: IC REG/DRIVER SECONDARY SOT23-5
• Manufacturer: National Semiconductor

Specifications of LM3411AM5-5.0/NOPB

• Reference Type: Shunt
• Voltage - Output: 5V
• Tolerance: ±0.5%
• Number Of Channels: 1
• Current - Cathode: 110µA
• Current - Output: 15mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -
• Temperature Coefficient: -
• Current - Quiescent: -
• Other names: LM3411AM5-5.0/NOPBTR

Applications Information
The LM3411 regulator/driver provides the reference and
feedback drive functions in a regulated power supply. It can
also be used together with many different types of regula-
tors, (both linear and switching) as well as other power
semiconductor devices to add precision and improve regu-
lation specifications. Output voltage tolerances better than
0.5% are possible without using trim pots or precision resis-
tors.
One of the main applications of the LM3411 is to drive an
opto-isolator to provide feedback signal isolation in a switch-
ing regulator circuit. For low current applications, (up to 250
mA) the circuit shown in Figure 3 provides good regulation
and complete input/output electrical isolation.
For an input voltage of 15V, this circuit can provide an output
of either 3.3V or 5V with a load current up to 250 mA with
FIGURE 4. Isolated 1.5A Flyback Switching Regulator Using a LM2577
FIGURE 3. Isolated 250 mA Flyback Switching Regulator
9
excellent regulation characteristics. With the part values
shown, this circuit operates at 80 kHz., and can be synchro-
nized to a clock or an additional LM3578. (See LM1578 data
sheet for additional information.)
An isolated DC/DC flyback converter capable of higher out-
put current is shown in Figure 4. This circuit utilizes the
LM2577 SIMPLE SWITCHER
Pulse Width Modulation (PWM), power switch and protection
functions, while the LM3411 provides the voltage reference,
gain and opto coupler drive functions. In this circuit, the
reference and error amplifier in the LM2577 are not used
(note that the feedback pin is grounded). The gain is pro-
vided by the LM3411. Since the voltage reference is located
on the secondary side of the transformer, this circuit provides
very good regulation specifications.
01198715
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voltage regulator for the
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