MIC5020YM Micrel Inc, MIC5020YM Datasheet - Page 5

• Manufacturer Part Number: MIC5020YM
• Description: IC DRIVER MOSF LO SIDE HS 8-SOIC
• Manufacturer: Micrel Inc

Specifications of MIC5020YM

• Configuration: Low-Side
• Input Type: Non-Inverting
• Delay Time: 400ns
• Number Of Configurations: 1
• Number Of Outputs: 1
• Voltage - Supply: 11 V ~ 50 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Device Type: Low Side
• Module Configuration: Low Side
• Input Delay: 400ns
• Output Delay: 900ns
• Supply Voltage Range: 11V To 50V
• Driver Case Style: SOIC
• No. Of Pins: 8
• Number Of Drivers: 1
• Driver Configuration: Non-Inverting
• Driver Type: Low Side
• Input Logic Level: TTL
• Rise Time: 1500ns
• Fall Time: 1500ns
• Frequency (max): 150MHz
• Operating Supply Voltage (max): 50V
• Operating Supply Voltage (min): 11V
• Turn Off Delay Time: 1.5ps
• Turn On Delay Time (max): 800ps
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Peak: -
• High Side Voltage - Max (bootstrap): -
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-1818-5; MIC5020YM

Functional Description
Refer to the MIC5020 block diagram.
Input
A signal greater than 1.4V (nominal) applied to the MIC5020
INPUT
turning the external MOSFET on.
An internal pull-down resistor insures that an open
remains low, keeping the external MOSFET turned off.
Gate Output
Rapid rise and fall times on the
because each input state change triggers a one-shot which
activates a high-value current sink (10I
This draws a high current through a current mirror circuit
causing the output transistors to quickly charge or discharge
the external MOSFET’s gate.
A second current sink continuously draws the lower value
of current used to maintain the gate voltage for the selected
state.
An internal 15V Zener diode protects the external MOSFET
by limiting the gate output voltage when V
to higher voltages.
Overcurrent Limiting
Current source I
external capacitor connected to C
Applications Information
The MIC5020 MOSFET driver is intended for low-side switch-
ing applications where higher supply voltage, overcurrent
sensing, and moderate speed are required.
Supply Voltage
A feature of the MIC5020 is that its supply voltage rating of
up to 50V is higher than many other low-side drivers.
The minimum supply voltage required to fully enhance an
N-channel MOSFET is 11V.
A lower supply voltage may be used with logic level MOS-
FETs. Approximately 6V is needed to provide 5V of gate
enhancement.
Low-Side Switch Circuit Advantages
A moderate-speed low-side driver is generally much faster
than a comparable high-side driver. The MIC5020 can pro-
vide the gate drive switching times and low propagation delay
times that are necessary for high-frequency high-efficiency
circuit operation in PWM (pulse width modulation) designs
used for motor control, SMPS (switch mode power supply)
and heating element control. Switched loads (on/off) can
benefit from the MIC5020’s fast switching times by allowing
use of MOSFETs with smaller safe operating areas. (Larger
MOSFETs are often required when using slower drivers.)
Overcurrent Limiting
A 50mV comparator is provided for current sensing. The low
level trip point minimizes I
are used for current sensing. Flexibility in choosing drain or
source side sensing is provided by access to both
July 2005
MIC5020
causes gate enhancement on an external MOSFET
1
charges C
2
R losses when power resistors
INT
upon power up. An optional
GATE
T
is discharged through
output are possible
2
) for a short time.
DD
is connected
SENSE
INPUT
+
5
MOSFET Q1.
A fault condition (> 50mV from
the overcurrent comparator to enable current sink 2I
overcomes current source I
When C
off the
and C
When the
signal is removed from the sense inputs which deactivates
current sink 2I
connected to C
retry while the capacitor(s) recharge. Retry delay is increased
by connecting a capacitor to C
The retry cycle will continue until the the fault is removed or
the input is changed to TTL low.
If C
fault condition.
Fault Output
The
active at approximately the same time the output is disabled
by a fault condition (5µs after an overcurrent condition is
sensed). The
successive retry (5µs).
and
The adjustable retry feature can be used to handle loads
with high initial currents, such as lamps, motors, or heating
elements and can be adjusted from the C
C
ing overcurrent detection.
C
retry . The default duty cycle (C
20%. Refer to the electrical characteristics when selecting
a capacitor for a reduced duty cycle.
C
Increasing the duty cycle increases the power dissipation in
the load and MOSFET. Circuits may become unstable at a
duty cycles of about 75% or higher, depending on the condi-
tions. Caution: The MIC5020 may be damaged if the voltage
on C
An overcurrent condition is externally signaled by an open
collector (
The MIC5020 may be used without current sensing by con-
necting
Current Sense Resistors
Lead length can be significant when using low value (< 1Ω)
resistors for current sensing. Errors caused by lead length
can be avoided by using four-terminal current sensing re-
sistors. Four-terminal resistors are available from several
manufacturers.
T
T
T
to ground causes maintained gate drive shutdown follow-
open, or through a capacitor to ground, causes automatic
through a pull-up resistor to V
T
SENSE
FAULT
T
is connected to ground, the circuit will not retry upon a
T
exceeds the absolute maximum rating.
GATE
are ready to be charged.
SENSE
INT
GATE
FAULT
is discharged, the
output is an open collector transistor.
– comparator inputs.
output; the
1
FAULT
. This allows C
output turns the MOSFET off, the overcurrent
T
+ and
) output.
to recharge. A Schmitt trigger delays the
output is open circuit (off) during each
SENSE
FAULT
1
to discharge C
– to ground.
INPUT
INT
SENSE
T
output is enabled; and C
DD
(optional).
and the optional capacitor
T
increases the duty cycle.
open) is approximately
is disabled, which turns
+ to
T
INT
SENSE
connection.
in a short time.
Micrel, Inc.
–) causes
MIC5020
FAULT
1
which
INT
is