LM25069MM-2EVAL National Semiconductor, LM25069MM-2EVAL Datasheet - Page 17

• Manufacturer Part Number: LM25069MM-2EVAL
• Description: BOARD EVALUATION LM25069
• Manufacturer: National Semiconductor

Specifications of LM25069MM-2EVAL

• Main Purpose: Power Management, Hot Swap Controller
• Embedded: No
• Utilized Ic / Part: LM25069-2
• Primary Attributes: High Side MOSFET Driver, Inrush Current Limiting
• Secondary Attributes: Auto Restart, 2.9 V ~ 17 V Supply
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The four resistor values are calculated as follows:
(V
(V
Option D: The OVLO function can be disabled by grounding
the OVLO pin. The UVLO thresholds are set as described in
Option B or Option C.
- Choose the upper and lower UVLO thresholds (V
UVL
-Choose the upper and lower OVLO threshold (V
OVL
FIGURE 12. Programming the Four Thresholds
).
).
FIGURE 13. UVLO = POR with Shutdown/Restart Control
OVH
UVH
) and
30086741
) and
17
As an example, assume the application requires the following
thresholds: V
14V. Therefore V
sistor values are:
R1 = 50 kΩ, R2 = 10 kΩ
R3 = 75 kΩ, R4 = 6.07 kΩ
Where the R1-R4 resistor values are known, the threshold
voltages and hysteresis are calculated from the following:
Option C: The minimum UVLO level is obtained by connect-
ing the UVLO pin to VIN as shown in
on when the VIN voltage reaches the POR threshold (
The OVLO thresholds are set using R3, R4. Their values are
calculated using the procedure in Option B.
POWER GOOD PIN
During turn-on, the Power Good pin (PGD) is high until the
voltage at VIN increases above
low, remaining low as the VIN voltage increases. When the
voltage at OUT increases to within 1.3V of the SENSE pin
(V
DS
<1.3V), PGD switches high. PGD switches low if the
UVH
= 8V, V
UV(HYS)
V
V
UV(HYS)
OV(HYS)
UVL
= 1V, and V
= R1 x 20 µA
= R3 x 20 µA
= 7V, V
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≊
1.6V. PGD then switches
Figure
OVH
OV(HYS)
= 15.5V, and V
13. Q1 is switched
= 1.5V. The re-
www.national.com
≊
2.6V).
OVL
=