LM5069MMX-1/NOPB National Semiconductor, LM5069MMX-1/NOPB Datasheet - Page 16

• Manufacturer Part Number: LM5069MMX-1/NOPB
• Description: IC CTLR HOT SWAP 48V 10-MSOP
• Manufacturer: National Semiconductor
• Type: Hot-Swap Controllerr

Specifications of LM5069MMX-1/NOPB

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 9 V ~ 80 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
• For Use With: LM5069EVAL - BOARD EVALUATION LM5069
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM5069MMX-1

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For example, if C
end of the restart time, Q1 is switched on. If the fault is still
present, the fault timeout and restart sequence repeats. The
on-time duty cycle of Q1 is approximately 0.5% in this mode.
UVLO, OVLO
By programming the UVLO and OVLO thresholds the
LM5069 enables the series pass device (Q1) when the input
supply voltage (V
If V
threshold, Q1 is switched off, denying power to the load. Hys-
teresis is provided for each threshold.
Option A: The configuration shown in Figure 12 requires
three resistors (R1-R3) to set the thresholds.
The procedure to calculate the resistor values is as follows:
UVLO threshold (V
advance 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:
The lower OVLO threshold is calculated from:
FIGURE 12. UVLO and OVLO Thresholds Set By R1-R3
- Choose the upper UVLO threshold (V
- Choose the upper OVLO threshold (V
- The lower OVLO threshold (V
SYS
is below the UVLO threshold, or above the OVLO
SYS
T
= 0.33 µF, t
UVL
) is within the desired operational range.
= C
).
T
OVL
x 9.4 x 10
RESTART
must be accurately defined in
OVL
6
) cannot be chosen in
= 3.1 seconds. At the
UVH
OVH
), and the lower
).
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As an example, assume the application requires the following
thresholds: V
The lower OVLO threshold calculates to 55.8V, and the OVLO
hysteresis is 4.2V. Note that the OVLO hysteresis is always
slightly greater than the UVLO hysteresis in this configuration.
When the R1-R3 resistor values are known, the threshold
voltages and hysteresis are calculated from the following:
Option B: If all four thresholds must be accurately defined,
the configuration in Figure 13 can be used.
The four resistor values are calculated as follows:
FIGURE 13. Programming the Four Thresholds
UVH
V
= 36V, V
OV(HYS)
V
UV(HYS)
= (R1 + R2) x 21 µA
UVL
= R1 x 21 µA
= 32V, V
OVH
= 60V.
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