LNBH23PPR STMicroelectronics, LNBH23PPR Datasheet - Page 8

• Manufacturer Part Number: LNBH23PPR
• Description: IC LNB SUPPLY/CTRL POWERSSO-24
• Manufacturer: STMicroelectronics

Specifications of LNBH23PPR

• Applications: Converter, Analog and Digital STB Receivers/SatTV
• Voltage - Input: 8 ~ 15 V
• Number Of Outputs: 1
• Voltage - Output: 13.4V, 18.5V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: PowerSSO-24
• Output Voltage: 25 V
• Output Current: 1000 mA
• Input Voltage: 8 V to 15 V
• Switching Frequency: 220 KHz
• Operating Temperature Range: - 25 C to + 125 C
• Mounting Style: Through Hole
• Duty Cycle (max): 57 %
• For Use With: 497-8717 - DEMO BOARD BASED ON LNBH23497-8336 - BOARD EVAL BASED ON LNBH23
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6121-2

Application information
2.11
2.12
2.13
Note:
8/32
1
Output current limit selection
The linear regulator current limit threshold can be set by an external resistor connected to
I
I
where R
limit threshold is 1.0 A typ with R
threshold value.
Over-current and short circuit protection and diagnostic
In order to reduce the total power dissipation during an overload or a short circuit condition,
the device is provided with a dynamic short circuit protection. It is possible to set the short
circuit current protection either statically (simple current clamp) or dynamically by the PCL
bit of the I²C SR. When the PCL (pulsed current limiting) bit is set lo LOW, the over current
protection circuit works dynamically: as soon as an overload is detected, the output current
is provided for 90 ms (typ.), after that the output is set in shut-down for a time T
typically 900 ms. Simultaneously the diagnostic OLF I²C bit of the system register is set to
"1". After this time has elapsed, the output is resumed for a time T
(typ.). At the end of T
through T
operation is resumed and the OLF diagnostic bit is reset to LOW. Typical T
990 ms and an internal timer determines it. This dynamic operation can greatly reduce the
power dissipation in short circuit condition, still ensuring excellent power-on start-up in most
conditions. However, there could be some cases in which a highly capacitive load on the
output may cause a difficult start-up when the dynamic protection is chosen. This can be
solved by initiating any power start-up in static mode (PCL=1) and, then, switching to the
dynamic mode (PCL=0) after a chosen amount of time depending on the output
capacitance. Also in static mode, the diagnostic OLF bit goes to "1" when the current clamp
limit is reached and returns LOW when the overload condition is cleared.
Thermal protection and diagnostic
The LNBH23 is also protected against overheating: when the junction temperature exceeds
150 °C (typ.), the step-up converter and the liner regulator are shut-off, and the diagnostic
OTF SR bit is set to "1". Normal operation is resumed and the OTF bit is reset to LOW when
the junction is cooled down to 135 °C (typ.).
External components are needed to comply to bidirectional DiSEqC™ bus hardware
requirements. Full compliance of the whole application with DiSEqC™ specifications is not
implied by the use of this IC. NOTICE: DiSEqC™ is a trademark of EUTELSAT. I²C is
trademark of Philips Semiconductors.
SEL
MAX
[A] = 10000/R
pin. The resistor value defines the output current limit by the equation:
SEL
OFF
is the resistor connected between I
and T
SEL
ON
ON
. At the end of a full T
, if the overload is still detected, the protection circuit will cycle again
Doc ID 13356 Rev 7
SEL
=10 kΩ. The above equation defines the typical
ON
SEL
in which no overload is detected, normal
and GND. The highest selectable current
ON
=1/10 T
ON
OFF
+T
OFF
OFF
= 90 ms
LNBH23
of
time is