MIC5031BM [MICREL]
High-Speed High-Side MOSFET Driver; 高速高边MOSFET驱动器
| 型号： | MIC5031BM |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | High-Speed High-Side MOSFET Driver |
| 文件： | 总8页 (文件大小：90K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MIC5031
High-Speed High-Side MOSFET Driver
Not Recommended for New Designs
General Description
Features
The MIC5031 MOSFET driver is designed to switch an
N-channel enhancement-type MOSFET from a TTL control
signal in a high-side switch application. The MIC5031 pro-
vides overcurrent protection, can accommodate loads with
high-inrush current, and is designed to survive automotive
power disturbances. This driver is suitable for up to 30kHz
PWM operation with 0% to 100% duty cycle.
• +4.5V to +30V operation
• Fast gate drive
(rise time = 70ns, fall time = 50ns,
with 1000pF load and 5V supply)
• Overcurrent detection across MOSFET
• Overcurrent shutdown delay
• Charge pump for high-side dc applications
• TTL compatible input
• Overtemperature shutdown
• Automotive load dump protection
• Reverse battery protection
• Open-collector fault flag
The MIC5031 is powered by the +4.5V to +30V load voltage.
An external bootstrap capacitor and internal charge pump
drive the gate output higher than the supply voltage. The
bootstrap capacitor provides speed, while the charge pump
can sustain the high gate output voltage continuously.
• Near zero-current disable state
The MIC5031 features a resistor programmable overcurrent
shutdown (circuit breaker) function that monitors the voltage
drop across the external MOSFET. A capacitor program-
mableshutdowndelayallowsahigh-inrushcurrentloadtobe
energized without causing undesired shutdown. An open-
load detection feature is included and can be used by adding
an external high-value resistor.
Applications
• Automotive power switch
• Automotive PWM control
• Circuit breaker
• PWM circuits
Ordering Information
TheMIC5031isprotectedagainstautomotiveloaddumpand
reverse battery conditions. The driver is also protected from
excessive power dissipation by an internal overtemperature
shutdown circuit.
Part Number
Temperature Range
Package
MIC5031BM
–40°C to +85°C
16-lead SOIC
An open-collector fault flag output indicates overcurrent,
overtemperature, or open-load fault conditions.
Typical Application
+4.5V to +30V
51k
100µF
100nF
MIC5031
10k§
7
1
Normal
Fault
VDD
FLG
RV
G
0.01µF§
1k*
Enable
Disable
4
3
14
16
12
13
15
6
EN
IRF540
On
Off
100k†
CTL
0.1µF
10
8
0.01µF
0.01µF
CP1+
CP1–
CP2+
CP2–
GND
CB
S
11
9
RI
0.1µF
12k*
M
CS
DLY
2N5822
5
2
50pF‡
15µF
*
Sets Overcurrent Trip to MOSFET VDS ≈ 102mV
†
‡
§
Optional Resistor for Open-Load Detection
Optional Capacitor for Overcurrent Delay
Optional Resistor and Capacitor for Power-up Sequence
High-Side Power Switch and Circuit Breaker
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
August 1999
1
MIC5031
MIC5031
Micrel
Pin Configuration
FLG
DLY
CTL
EN
G
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
RI
RV
S
GND
CS
CB
CP2+
CP1+
CP2–
VDD
CP1–
16-lead SOIC (M)
Pin Description
Pin Number
Pin Name
Pin Function
1
FLG
Fault Flag: (Output): Open-collector output sinks current upon overcurrent,
open-load, or overtemperature detection. 10mA maximum load.
2
3
DLY
CTL
Overcurrent Delay Time Capacitor: Optional. Capacitor to ground delays
activation of overcurrent shutdown.
Control (Input): TTL compatible on/off control input. Logic high drives the
gate output above the supply voltage. Logic low forces the gate output near
ground. Logic low also resets the overcurrent fault latch.
4
EN
Enable (Input): CMOS compatible input. Logic high enables the charge
pump. Logic low disables the charge pump and draws near zero supply
current.
5
6
GND
CS
Ground: Power return.
Internal Supply Storage Capacitor: 10µF external capacitor to GND.
Provides additional current to internal circuitry during switching transitions.
7
VDD
CP1–
CP2–
CP1+
CP2+
CB
Supply (Input): +4.5V to +30V supply.
8
Charge Pump Capacitor #1: Refer to CP1+.
9
Charge Pump Capacitor #2: Refer to CP2+.
10
11
12
13
14
Charge Pump Capacitor #1: External 0.01µF voltage tripler capacitor.
Charge Pump Capacitor #2: External 0.01µF voltage tripler capacitor.
Bootstrap Capacitor: 0.1µF capacitor to source for fastest rise time.
Source: Source connection to external MOSFET.
S
RV
Reference Voltage Resistor: Resistor to VDD provides a reference voltage
drop. A voltage drop across the external MOSFET that is greater than the
voltage drop across the reference resistor indicates an overcurrent condition.
(Refer to applications section) Zero temperature coefficient resistor
recommended.
15
16
RI
G
Reference Current Resistor: Resistor to GND sets constant current value
through RV resistor (Refer to applications section) and matches tempera-
ture compensation of RV resistor. Zero temperature coefficient resistor
recommended.
Gate (Output) : Gate connection to external MOSFET.
MIC5031
2
August 1999
MIC5031
Micrel
Absolute Maximum Ratings
Operating Ratings
Supply Voltage (V ) ..................................................+36V
Supply Voltage (V ) ................................... +4.5V to +30V
DD
DD
Enable Input Voltage (V ) .........................................+36V
Ambient Temperature Range (T )
EN
A
A-temperature range ............................ –55°C to +125°C
B-temperature range .............................. –40°C to +85°C
Control Input Voltage (V
)
CTL
V
V
≤ 15V..................................................................V
> 15V ...............................................................+15V
) .........................................+36V
DD
DD
DD
Package Thermal Resistance (θ )
JA
SOIC .................................................................115°C/W
Flag Output Voltage (V
FLG
Reference Voltage Input (V )....................................+36V
RV
Junction Temperature (T ) ........................................ 150°C
J
Electrical Characteristics
VDD = 12V; CB = 0.1µF, CP1 = CP2 = 0.01µF; TA = 25°C; unless noted
Symbol
Parameter
Condition
Min
Typ
0.3
1.0
0.72
–0.2
1.55
0.5
0.1
6
Max
Units
µA
mA
mA
µA
V
IDD
Supply current
VEN = 0V, VCTL = 0V
VEN = 12V, VCTL = 0V
VEN = 12V, VCTL = 5V
VDD = –12V
3
IDDR
VCTL
VCTLH
ICTL
VEN
IEN
Reverse voltage leakage current
Control input voltage threshold
Control input voltage hysteresis
Control input current
–5
0.2
1.0
1
V
µA
V
Enable input voltage threshold
Enable input current
0.1
1
µA
mV
µA
µs
V
VIOS
IRV
tSHDL
VG
tDLR
tR
tDLF
tF
Overcurrent comparator offset
Current limit reference current
Overcurrent shut down delay
Gate drive voltage
±5
RRI = 12.0k
97
100
16
103
CDLY = 50pF
VEN = 12V, VCTL = 5V
VEN = 12V, CL = 1000p
CL = 1000pF
25
Gate turn-on delay
420
90
ns
ns
ns
ns
V
Gate rise time
Gate turnoff delay
CL = 1000pF
300
50
Gate fall time
CL = 1000pF
VOLTH
TOT
TOTH
fCP
Open-load threshold voltage
Overtemperature shut down
Overtemp. shut down hysteresis
Charge pump frequency
Flag active voltage
VEN = 12V, VCTL = 0V
VEN = 12V, VCTL = 5V
VEN = 12V, VCTL = 5V
VDD = 5V, Note 1
open load error, IFLG = 2mA (sink)
6.3
140
°C
°C
kHz
V
10
190
0.2
VFLG
General Note: Devices are ESD protected; however, handling precautions are recommended.
Note 1: Oscillator burst mode at V ≥ 5.2V.
DD
August 1999
3
MIC5031
MIC5031
Micrel
Block Diagram
VSUPPLY
C1
CP1– CP1+
C2
CP2– CP1+
VDD
Charge Pump
Oscillator
CB
CS
Bias
Regulator
Voltage
Tripler
Gate Drive
Regulator
C3
Osc. Disable
Gate
Driver
Open-Load
Detect
Resistor
(Optional)
External
N-Channel
MOSFET
G
Reset
Logic
CTL
(TTL)
Open-Load Detect
S
EN
(CMOS)
Current Limit
Delay
Voltage
Comp.
R1
C4
RV
DLY
1.23V
Ref.
Current
Amp.
Bandgap
Reference
nIcuitvLeoad
Overcurrent
Delay
Capacitor
(Optional)
RI
Lockout
Latch
R2
FLAG
Overtemp.
Detect
MIC5031
GND
MIC5031 with External Components
MIC5031
4
August 1999
MIC5031
Micrel
Current Sense
Functional Description
Refer to the “Voltage Reference (Simplified)” diagram.
Refer to “Functional Diagram.”
The MIC5031 detects an overcurrent condition by comparing
the voltage drop across the external MOSFET to a reference
The MIC5031 is a noninverting device. Applying a CMOS
logic high signal to EN (enable input) activates the driver’s
internal circuitry. Applying a TTL logic high signal to CTL
(control input) produces gate drive output. The G (gate)
output is used to turn on an external N-channel MOSFET.
voltage drop created across R1. If V
exceeds V , a
DS
R1
comparator (not shown) shuts off the external MOSFET by
way of the current limit delay, lockout latch, and logic.
The bandgap reference, op amp and NPN create a constant
voltage (1.23V) across R2. This results in a constant current,
Control
CTL (control) is a TTL compatible input. The threshold is
approximately 1.4V, independent of the supply voltage.
I
, through R2. Ignoring a small amount of base current, the
R2
same current (I ) flows through R1. R1 is selected to
R2
The falling edge of a signal applied to CTL also resets the
overcurrent lockout latch.
achievethedesiredreferencevoltagedrop, V . Refertothe
R1
applications section for formulas.
Enable
Supply
EN (enable) is a CMOS compatible input. EN enables or
disablesallinternalcircuitry. Theenablethresholdisapproxi-
mately half the supply voltage. The MIC5031 supply current
is near zero when the driver is disabled (low). See “Applica-
tions Information: Power-Up Sequence.”
External
N-Channel
MOSFET
IR2
VR1
VDS
R1
RV
RI
1.23V
Bandgap
Reference
Charge Pump
The charge pump produces a voltage that is higher than the
supply voltage. This higher voltage is required to drive the
external N-channel MOSFET in high-side switch circuits.
IR2
R2
1.23V
The charge pump consists of an oscillator and a voltage
tripler. When the driver is enabled, the charge pump is
switched on and off to regulate its output voltage.
Voltage Reference (Simplified)
An overcurrent condition also activates the fault flag output
when the lockout latch is activated.
External capacitors C1 and C2 are required. The charge
pump will not operate without these capacitors.
Overcurrent-Shutdown Delay
Bootstrap Capacitor
The overcurrent-shutdown delay circuit permits a delay be-
tween overcurrent detection and latch activation for high-
inrush current loads.
The external bootstrap capacitor is necessary to achieve the
fastestgaterisetimes. Thebootstrapcapacitor(C3)supplies
additional current at a higher voltage to the gate drive
regulator as the MOSFET is switched on.
The delay can be increased by adding capacitance from DLY
to GND.
When the MOSFET is off, the gate drive regulator voltage is
applied to the boost capacitor . As the MOSFET turns on, the
MOSFET source-to-ground voltage increases. The increas-
ing source voltage is added to the voltage across the capaci-
tor for a voltage doubling effect.
Open-Load Detect
The open load detect resistor is an external high-value pull-
up resistor that causes the source voltage of the external
MOSFET to increase when the load is missing.
Gate Drive Regulator
The MIC5031 monitors the S-pin voltage only when the gate
driver is off. If the voltage on the S-pin rises above the open-
load detect threshold, the fault flag is activated.
The gate drive regulator manages the voltage from the
bootstrap capacitor, the supply, and the charge pump.
Overtemperature Detect
The gate drive regulator charges the bootstrap capacitor
when the MOSFET is off and limits the voltage from the
bootstrap capacitor as the MOSFET is switched on. It also
performsskip-modecontrolbyswitchingthechargepumpon
and off to regulate the gate drive output voltage.
The overtemperature detect circuit switches the logic to turn
the output off at approximately 140°C. An overtemperature
shutdownconditionisrestoredtonormalautomatically When
the device cools to about 130°C (10°C hysteresis).
Gate Output
An overtemperature condition also activates the fault flag
output.
When the MIC5031 is enabled and CTL is high, the gate
driver steers regulated voltage to G (gate output). When CTL
is low, the gate driver grounds G. This respectively charges
or discharges the external MOSFET’s gate, .
Fault Flag
FLT (fault flag) is an open-collector NPN transistor. Fault is
active (pulls collector near ground) upon overcurrent, open-
load, or overtemperature.
August 1999
5
MIC5031
MIC5031
Micrel
Reference Current Resistor
Applications Information
Power-Up Sequence
Resistor R2 sets the reference current. For most applica-
tions, a reference current of 100µA is suggested.
The supply voltage (V ) must be applied to VDD before EN
DD
R1
is asserted. If EN is not required for the application, an RC
network must be used to delay the voltage rise applied to EN
with respect to VDD. See Figure 1.
R2 =
I
R2
where:
+4.5V to +30V
R2 = reference current resistor (Ω)
100µF
I
= reference current (A) [R2 = 12kΩ for
approximately 100µA]
R2
100nF
MIC5031
7
4
1
VDD
EN
FLG
RV
G
Reference Voltage Resistor
0.01µF
10k
14
16
12
13
15
6
The reference voltage resistor value is calculated from the
reference current and the reference voltage (overcurrent
drop voltage).
IRF540
On
Off
3
CTL
0.1µF
12k*
10
8
0.01µF
CP1+
CP1–
CP2+
CP2–
GND
CB
S
V
R1
R1=
11
9
0.01µF
RI
I
R2
0.1µF
M
CS
DLY
2N5822
where:
5
2
15µF
R1 = reference voltage resistor (Ω)
V
I
= reference voltage (V) [see above]
R1
= reference current (A) [see above]
Figure 1. Enable Application
R2
Overcurrent Delay Capacitor
Refer to “Typical Application” for controlling EN from open-
collector or open-drain logic. The 10k resistor and 0.01µF
capacitor connected to VDD, GND, and EN keep EN low
duringpowerupbeforetheopen-collectororopen-drainlogic
becomes active.
For lamp switching applications, the delay capacitor (C
)
DLY
may be as high as several microfarads. Lamps often have an
inrush current of 10× their steady-state operating current. In
PWM applications, pay attention to the input frequency vs.
the overcurrent delay. They can conflict with each other if not
properly planned.
The 10k resistor and 0.01µF capacitor can be omitted if EN
is held low by the external logic until VDD is powered.
Overcurrent Detection
Using the MOSFET manufacturer’s data and the maximum
allowable load current, determine the maximum drain-to-
source voltage drop, V , that will occur across the external
DS
MOSFET in normal operation. This will also be the reference
voltage and the overcurrent trip voltage, V
.
R1
V
= maximum R
× maximum load current
R1
DS(on)
Supply
External
N-Channel
MOSFET
IR2
VR1
VDS
R1
RV
RI
1.23V
Bandgap
Reference
IR2
R2
1.23V
Figure 2. Resistor Calculations
MIC5031
6
August 1999
MIC5031
Micrel
Package Information
PIN 1
0.157 (3.99)
0.150 (3.81)
DIMENSIONS:
INCHES (MM)
0.020 (0.51)
REF
0.020 (0.51)
0.013 (0.33)
0.050 (1.27)
BSC
45°
0.0098 (0.249)
0.0040 (0.102)
0°–8°
0.050 (1.27)
0.016 (0.40)
0.394 (10.00)
0.386 (9.80)
SEATING
PLANE
0.0648 (1.646)
0.0434 (1.102)
0.244 (6.20)
0.228 (5.79)
16-Lead SOIC (M)
August 1999
7
MIC5031
MIC5031
Micrel
MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.
© 1999 Micrel Incorporated
MIC5031
8
August 1999
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