NCV8855BMNR2G ON Semiconductor, NCV8855BMNR2G Datasheet - Page 3

• Manufacturer Part Number: NCV8855BMNR2G
• Description: IC BUCK SYNC QUAD 40QFN
• Manufacturer: ON Semiconductor
• Type: Step-Down (Buck)r

Specifications of NCV8855BMNR2G

• Topology: Step-Down (Buck) (2), Linear (LDO) (2)
• Function: Automotive Radio and Instrument Cluster Power Supply
• Number Of Outputs: 4
• Frequency - Switching: 170kHz
• Voltage/current - Output 1: Controller
• Voltage/current - Output 2: Adjustable, 2.5A
• Voltage/current - Output 3: Controller
• W/led Driver: No
• W/supervisor: No
• W/sequencer: Yes
• Voltage - Supply: 9 V ~ 18 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 40-VFQFN Exposed Pad
• Voltage - Output: Adjustable
• Voltage - Input: 9 ~ 18 V
• Internal Switch(s): Both
• Synchronous Rectifier: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Other names: NCV8855BMNR2G; NCV8855BMNR2GOSTR

PIN FUNCTION DESCRIPTIONS
SWITCH−MODE POWER SUPPLY 1 (SMPS1) PIN CONNECTIONS
PINS NOT INTERNALLY CONNECTED TO SILICON
SWITCH−MODE POWER SUPPLY 2 (SMPS2) PIN CONNECTIONS
Pin No.
12 thru
EP
22
35
36
37
27
29
30
25
24
23
21
20
19
10
11
5
6
7
8
4
3
2
9
HOT_FLG
DRV_VPP
SYS_EN
LDO_EN
SW_FB1
SW_FB2
VIN_SW
Symbol
COMP1
COMP2
OCSET
HS_EN
DRAIL
AGND
PGND
5V_IC
SYNC
BST1
BST2
GH1
SN1
GL1
SN2
−
This pin is the output of the error amplifier and the non-inverting input of the PWM comparator. Use
this pin in conjunction with the SW_FB1 pin to compensate the voltage-mode control feedback
loop.
Main enable pin for the IC. A logic high on this pin will enable the part. Leaving this pin floating or driving it to
ground will place the IC in shutdown mode.
Enable pin for both LDO controllers. A logic high on this pin will enable both LDO controllers. If this pin is left
floating, an internal pull down keeps the LDOs disabled.
Enable pin for the high−side load switch. A logic high on this pin will enable the HSS. If this pin is left floating,
an internal pull down keeps the HSS disabled.
Thermal warning indicator. This pin provides an early warning signal of an impending thermal shutdown.
Output of the internal 7.2 V linear regulator. Bypass this pin with 1 mF to ground.
Output of the internal 5 V linear regulator. Bypass this pin with 0.1 mF to ground.
Output of the internal 4.2 V linear regulator. Bypass this pin with 0.1 mF to ground.
Synchronization pin. Use this pin to synchronize the internal oscillator to an external clock. If synchronization
is not used, connect this pin to AGND.
Analog ground. Reference point for internal signals.
Overcurrent set pin, used to set the current limit threshold. A resistor connected from this pin and the upper
MOSFET Drain sets the current limit protection level.
Output voltage feedback pin. Connect a resistor divider network to VOUT1 to set the desired output voltage.
This pin is the supply rail for the upper N−Channel MOSFET. An internal bootstrap diode brings DRV_VPP to
this pin. Connect a ceramic capacitor (C
0.1 mF.
GH1 is the output pin of the internal upper N−Channel MOSFET gate driver. Keep the trace from this pin to
the gate of the upper MOSFET as short as possible to achieve the best turn−on and turn−off performance
and to reduce electro−magnetic emissions.
This pin is the return path of the upper floating gate driver. Connect this pin to the source of the upper
MOSFET. This pin is also used to sense the current flowing through the upper MOSFETs.
GL1 is the output pin of the synchronous rectifier gate driver. Connect this pin to the lower N−channel
MOSFET.
This pin is the return path for SMPS1 lower MOSFET driver current. Connect this pin to the source of the
lower MOSFET.
Exposed pad of QFN package. Connect to printed circuit board ground to improve thermal performance.
These pins can be left floating or tied to ground to improve thermal performance.
This pin is the supply rail for the internal upper N−Channel MOSFET. Bypass this pin with a local ceramic
capacitor. Additional bulk capacitance may be required based off output requirements. Refer to application
section for more information.
Output voltage feedback pin. Connect a resistor divider network to VOUT2 to set the desired output voltage.
This pin is the output of the error amplifier and the non−inverting input of the PWM comparator. Use this pin
in conjunction with the SW_FB2 pin to compensate the voltage−controlled feedback loop.
This pin is the supply rail for the internal upper N−Channel MOSFET. An internal bootstrap diode brings
DRV_VPP to this pin. Connect a ceramic capacitor (C
for C
Source output of the internal upper N−channel MOSFET.
BST2
is 0.1 mF.
http://onsemi.com
BST1
3
) between this pin and the SN1 pin. A typical value for C
Description
BST2
) between this pin and the SN2 pin. A typical value
BST1
is