LM2743MTC National Semiconductor, LM2743MTC Datasheet - Page 11

• Manufacturer Part Number: LM2743MTC
• Description: SYNC SW CONTROL, 3V:6V, POWERWISE
• Manufacturer: National Semiconductor

Specifications of LM2743MTC

• Primary Input Voltage: 16V
• No. Of Outputs: 1
• Output Voltage: 13.5V
• Output Current: 20A
• Voltage Regulator Case Style: TSSOP
• No. Of Pins: 14
• Operating Temperature Range: -40°C To +125°C
• Svhc: No SVHC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application Information
Since V
Tracking Equation
The total value of the track resistor divider (Figure 3), R
R
R4=1K, for V
Case 2: Rise together until V
V
V
For R
The soft start reaches 0.6V at V
For V
SS
OUT1
4
, should be set below 10kΩ for better precision. Let
= V
4
OUT1
=1kΩ, R
= V
SS
FB
FIGURE 4. Timing Behavior of Case 1
= 0.6V,
FIGURE 5. Block Diagram of Case 2
OUT2
>
= V
1.8V, V
V
OUT1
FB
FB
3
= 1.8V
=500Ω (from Tracking Equation).
=0.6V, then
= V
= 5V and V
OUT2
OUT2
stays in regulation at 1.8V.
*(R
OUT2
FB2
OUT2
OUT1
/(R
=1.8V, R
FB1
=1.8V
equal 1.8V.
+R
FB2
(Continued)
3
=136Ω.
))
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3
and
11
Case 3: V
Assuming V
divider ratio 1:3 (R
equals SR
raises to 1.0V (V
is calculated from :
FIGURE 6. Timing Behavior of Case 2
OUT2
FIGURE 7. Block Diagram of Case 3
VSD
t
DELAY
OUT1
starts rising 3.0ms after V
= 0.333V/ms. During the delay time V
SD-IH
= 1.0(V) / 0.333(V/ms) = 3.0ms
3
t
slew rate SR
DELAY
= 500Ω and R
) as shown in Figure 8. The delay time
= V
SD-IH
VSD
4
/SR
= 1kΩ), the V
= 1V/ms and voltage
VSD
OUT1
SD
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slew rate
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SD