LM5069EVAL/NOPB National Semiconductor, LM5069EVAL/NOPB Datasheet - Page 5

• Manufacturer Part Number: LM5069EVAL/NOPB
• Description: BOARD EVALUATION LM5069
• Manufacturer: National Semiconductor

Specifications of LM5069EVAL/NOPB

• Main Purpose: Power Management, Hot Swap Controller
• Utilized Ic / Part: LM5069
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Other names: LM5069EVAL

UVLO/OVLO Input Voltage
Thresholds
As supplied, the input voltage UVLO thresholds on this eval-
uation board are approximately 34.4V increasing, and 32.4V
decreasing. The OVLO thresholds are approximately 77.7V
increasing, and 75.7V decreasing. The four thresholds are
determined by resistors R1-R4. The threshold voltage at each
pin is 2.50V, and internal 21µA current sources provide hys-
teresis for each threshold. See the data sheet for more details.
Option A: This evaluation board is supplied with the jumper
at JMP1 on pins 2-3, resulting in the configuration shown in
Figure 5.
To change the thresholds in this configuration, resistors R1-
R3 are calculated using the following procedure:
- Choose the upper UVLO threshold (V
UVLO threshold (V
- Choose the upper OVLO threshold (V
- The lower OVLO threshold (V
vance in this case, but is determined after the values for R1-
R3 are determined. If V
addition to the other three thresholds, see Option B below.
The resistors are calculated as follows:
FIGURE 5. UVLO, OVLO Inputs (Option A)
UVL
).
OVL
must be accurately defined in
OVL
) cannot be chosen in ad-
OVH
UVH
)
), and the lower
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The lower OVLO threshold is calculated from:
Option B: If all four thresholds must be determined accurate-
ly, move the jumper at JMP1 to pins 1-2, and add R4, resulting
in the configuration shown in Figure 6.
The four resistor values are calculated as follows:
- Choose the upper and lower UVLO thresholds (V
(V
- Choose the upper and lower OVLO threshold (V
(V
CAUTION: The Absolute Maximum Rating for the OVLO pin
is 7V. Do not let the voltage on OVLO exceed 7V when VIN
is at its maximum value. The Absolute Maximum Rating for
the UVLO pin is 100V.
UVL
OVL
).
).
FIGURE 6. UVLO, OVLO Inputs (Option B)
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OVH
UVH
) and
) and