L9848 STMicroelectronics, L9848 Datasheet - Page 14

• Manufacturer Part Number: L9848
• Description: IC DRIVER LO/HI SIDE OCTAL 28SOI
• Manufacturer: STMicroelectronics
• Type: High Side/Low Side Driverr

Specifications of L9848

• Input Type: SPI
• Number Of Outputs: 8
• Current - Output / Channel: 800mA
• Current - Peak Output: 1.3A
• Voltage - Supply: 4.75 V ~ 5.5 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: SO-28
• Rise Time: 30 ns
• Fall Time: 30 ns
• Supply Voltage (min): 4.75 V
• Supply Current: 6 mA
• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Number Of Drivers: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• On-state Resistance: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Functional description
3
3.1
3.2
3.2.1
14/27
Functional description
General features
The L9848 IC is a monolithic integrated circuit, which provides high flexibility for driving
medium loads. 8 outputs, whereof 6 (Output1-6) can be used as either internal low or high
side drives in any combination and 2 are dedicated low side outputs (Output7-8). The use of
this device reduces the I/O port requirements of the microprocessor by having serially
controlled outputs via a SPI interface. In addition, Output5-6 are capable of being PWMed
via an external pin (Input5-6). The 8bit SPI input is used to command the 8 output drivers
either ON or OFF and additional to indicate latched fault conditions that may have occurred.
Multiple L9848s may be daisy-chained with one additional microprocessor I/O port (CSn) for
each device. The implemented self-configuration allows the user to connect a high or low
side load to any of these outputs and the L9848 will drive them correctly as well as provide
proper fault mode operation with no other needed inputs. This device switch variable load
currents within the operation temperature range. The outputs are MOSFET drivers to
minimize Vdd current requirements. There's no V
the drains of high side outputs.
The L9848 meets all required specifications when the supply voltage applied to the drain(s)
of the outputs is within the operating range. For supply voltages applied to the drain(s) down
to 6.8V the part is functional however, it does not meet all parametric limits, i.e. output on-
state voltages.
Outputs - Common characteristics
The 6 self-configuring outputs (Outputs1-6) are able to drive either incandescent lamps,
inductive loads (non-PWMed), or resistive loads biased to VBatt. These outputs are enabled
and disabled via the SPI bus. Each of these outputs is short circuit current limited and has
an over-temperature protection as described under "Functional Description - Thermal
Shutdown".
When a high side configured output is commanded OFF after having been commanded ON,
the source voltage will go to the lesser negative of (VBatt-45V). This is due to the design of
the circuitry and the transconductance of the MOSFET.
When a low side configured output is commanded OFF after having been commanded ON,
the output voltage will rise to the internal zener clamp voltage (40 Vdc minimum) due to the
flyback of the inductive load.
Output 1-4
These four outputs can be used as either high or low side drives. Integrated current source
pull-ups and pull-downs are employed to correctly latch "open load" fault data. Both of these
current sources are needed to detect an open load state since these outputs self configure
as either high or low side drives.
Drain connections of output1-4 (DRN1-4)
These pins are connected to the drains of the n-channel MOSFET transistors.
Source connections of output1-4 (SRC1-4)
These pins are connected to the sources of the n-channel MOSFET transistors.
Batt
input pin however V
Batt
is connected to
L9848