pt5109 China Resources Powtech (Shanghai) Co., Ltd, pt5109 Datasheet - Page 5

• Manufacturer Part Number: pt5109
• Description: High-psrr 300ma Ldo
• Manufacturer: China Resources Powtech (Shanghai) Co., Ltd

1.806
1.804
1.802
1.800
1.798
1.796
1.794
1.792
1.790
1.788
1.786
SIMPLIFIED BLOCK DIAGRAM
In Figure 1, the block of Bandgap Reference provides the reference voltage of the LDO.
The op amp block is used as the error amplifier of the LDO by compare the reference with the output feedback
voltages. Its output controls the gate of a large PMOS driver and hereby adjusts the output voltage.
The resistor R
The Current Sense & Limit block senses the LDO output current and limits the output current from being too high.
This is mostly a short circuit protection feature.
TYPICAL PERFORMANCE CHARACTERISTICS
Unless otherwise specified: V
tied to V
China Resources Powtech (Shanghai) Limited
PT5109_DS Rev EN_2.0
-40
C
V
V
IN
EN
OUT
-20
= C
IN
= V
= 1.8V
.
OUT
IN
Output Voltage Temperature Characteristics
= 1uF
1
0
and R
V
V
IN
EN
20
2
form a voltage divider to provide the feedback voltage.
Temperature (
40
Reference
Bandgap
1.25V
Enable
IN
Figure1. Graph the PT5109 major functional blocks
= V
60
O
C)
OUT(nom)
80
+ 1V, V
100
120
EN
Current Limit
= V
Sense &
Current
WWW.CRPOWTECH.COM
IN
, C
IN
2.820
2.815
2.810
2.805
2.800
2.795
2.790
2.785
2.780
= C
-40
OUT
Shutdown
Thermal
C
V
V
IN
EN
OUT
= 1 uF Ceramic, T
-20
= C
= V
High-PSRR 300mA LDO
= 2.8V
OUT
IN
= 1uF
Output Voltage Temperature Characteristics
0
20
R1
R2
Temperature (
A
= +25°C, Enable pin is
40
GND
PT5109
60
V
O
OUT
C)
80
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120