AS1364-BTDT-AD austriamicrosystems, AS1364-BTDT-AD Datasheet - Page 9

• Manufacturer Part Number: AS1364-BTDT-AD
• Description: IC REG LDO 1A ADJ 8-TDFN
• Manufacturer: austriamicrosystems

Specifications of AS1364-BTDT-AD

• Package / Case: 8-WDFN Exposed Pad
• Mounting Type: Surface Mount
• Current - Output: 1A (Min)
• Voltage - Output: 1.2 ~ 5.3 V
• Voltage - Input: 2 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Regulator Topology: Positive Adjustable
• Voltage - Dropout (typical): 0.14V @ 1A
• Number Of Regulators: 1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Limit (min): -

AS1364
Data Sheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1364 output voltage is factory-trimmed or is adjustable from +1.2 to +5V, and is guaranteed to supply 1A of out-
put current. The device consists of a +1.20V internal reference, error amplifier, MOSFET driver, P-channel pass tran-
sistor, internal feedback voltage-divider and a comparator
Figure 16. Bypass Version Typical Application
The +1.20V reference is connected to the inverting input of the error amplifier, which compares this reference with the
selected feedback voltage and amplifies the difference.
The MOSFET driver reads the error signal and applies the appropriate drive to the P-channel transistor. If the feedback
voltage is lower than the reference, the pass transistor gate is pulled lower, allowing more current to pass increasing
the output voltage. If the feedback voltage is too high, the pass transistor gate is pulled up, allowing less current to
pass to the output.
The low V
to go low.
The output voltage is fed back through either an internal resistor-divider connected to OUT or an external resistor net-
work connected to SET. The comparator examines V
50mV, the internal feedback path is used and the output is regulated to the factory-preset voltage.
Internal P-Channel Pass Transistor
The AS1364 features a 1A P-channel MOSFET pass transistor and consumes only a maximum of 200µA of quiescent
current under heavy loads as well as in dropout.
Output Voltage Selection
At the factory trimmed versions of the AS1364 offering the bypass pin
an internally trimmed voltage
For the adjustable AS1364-AD, an output voltage between +1.2V and +5V can be set by using two external resistors
(see Figure
Where:
V
A simplification of R
Since the input bias current at SET is less than 100nA, large resistance values can be used for R1 and R2 to minimize
power consumption and therefore increasing efficiency.
Note: Up to 125kΩ is acceptable for R2. If the SET pin is connected to GND without a resistor, 3.3V will be set as out-
In preset voltage mode, the impedance from SET to GND should be less than 10kΩ or spurious conditions may cause
the voltage at SET to exceed the 50mV threshold.
www.austriamicrosystems.com
SET/BYP
put voltage.
= +1.20V.
OUT
17). In this mode, V
V
comparator senses when the feedback voltage has dropped 6% below its expected level, causing POK
IN
1
and R
C
4.7µF
IN
On
Off
2
selection is:
(see Ordering Information on page
OUT
is determined by:
GND
R
EN
IN
IN
4
8
3
2
1
= R
V
SET/BYP
2
((V
AS1364
OUT
Revision 1.00
SET/BYP
(1 + (R
/ V
(see Figure 1 on page
SET/BYP
1
and selects the feedback path. If V
/ R
13).
2
))
) – 1)
6
OUT
5
OUT
1
POK
7
SET/BYP
(see Figure
Reset Output
1).
16), the output voltage is then set to
C
10nF
BYP
SET/BYP
C
4.7µF
OUT
V
OUT
is below
(EQ 1)
(EQ 2)
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