NCV8509PDW18R2G ON Semiconductor, NCV8509PDW18R2G Datasheet - Page 13

• Manufacturer Part Number: NCV8509PDW18R2G
• Description: IC REG VOLT DUAL SEQ LIN 16SOIC
• Manufacturer: ON Semiconductor

Specifications of NCV8509PDW18R2G

• Regulator Topology: Positive Fixed
• Voltage - Output: 3.3V, 1.8V
• Voltage - Input: Up to 50V
• Voltage - Dropout (typical): 0.4V @ 100mA
• Number Of Regulators: 2
• Current - Limit (min): 115mA, 105mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (7.5mm Width) Exposed Pad, 16-eSOIC, 16-HSOIC
• Polarity: Positive
• Number Of Outputs: 2
• Output Type: Fixed
• Output Voltage: 1.8 V, 3.3 V
• Output Current: 0.115 A, 0.1 A
• Line Regulation: 50 mV
• Load Regulation: 50 mV
• Dropout Voltage (max): 0.2 V
• Input Voltage Max: 50 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Voltage Regulation Accuracy: 2 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: NCV8509PDW18R2GOS

Why Use a Power Shunt?
power dissipation on the integrated circuit.
dissipates 1.35 W as shown.
into head room issues at 6.0 V and would only be able to
drive 21.5 mA as shown in Figure 45 before causing the
2.5 V output to collapse.
current back in at low voltage operation. So the power is
moved off chip at high voltage where it is needed most.
resistor value (29 Ω) without the power shunt for 6.0 V
operation.
of power is dissipated off chip compared to Figure 44 with
1.35 W.
The power shunt circuitry helps manage and optimize
Figure 44 shows a 100 mA load. A 135 Ω resistor
Without the power shunt, the 135 Ω resistor would run
Figure 46 shows the power shunt circuitry adding the
To further clarify, Figure 47 shows the maximum allowed
Figure 48 shows the scenario at high voltage. Only 290 mW
Figure 44.
R
EX
R
Figure 42. Power Shunt
135 Ω
V
LOAD
OUT2
V
V
IN1
IN2
V
18 V
100 mA
V
4.5 V
V
2.5 V
100 mA
IN1
IN2
OUT2
Regulator
Voltage
http://onsemi.com
+
600 mV
−
R
135 Ω
Figure 45.
LOAD
13
V
6.0 V
21.5 mA
V
3.1 V
V
2.5 V
21.5 mA
IN1
IN2
OUT2
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
+
600 mV
−
0
R
0
LOAD
29 Ω
Figure 47.
Figure 43. Power On Chip
V
6.0 V
100 mA
V
3.1 V
V
2.5 V
100 mA
IN1
IN2
OUT2
5
R
EX
10
> 138
V
IN
Figure 46.
15
78.5 mA
R
Figure 48.
LOAD
29 Ω
R
R
135 Ω
EX
I
OUT2
LOAD
< 138
R
20
= 100 mA
V
18 V
100 mA
V
15.1 V
V
2.5 V
100 mA
EX
IN1
IN2
OUT2
V
6.0 V
21.5 mA
V
4.5 V
V
2.5 V
100 mA
= 138
IN1
IN2
OUT2
25