MICREL MIC4123YML

MIC4123/4124/4125
Micrel, Inc.
MIC4123/4124/4125
Dual 3A-Peak Low-Side MOSFET Driver
Bipolar/CMOS/DMOS Process
General Description
Features
The MIC4123/4124/4125 family are highly reliable BiCMOS/DMOS buffer/driver/MOSFET drivers. They are higher
output current versions of the MIC4126/4127/4128, which
are improved versions of the MIC4426/4427/4428. All three
families are pin-compatible. The MIC4123/4124/4125 drivers are capable of giving reliable service in more demanding
electrical environments than their predecessors. They will
not latch under any conditions within their power and voltage
ratings. They can survive up to 5V of noise spiking, of either
polarity, on the ground pin. They can accept, without either
damage or logic upset, up to half an amp of reverse current
(either polarity) forced back into their outputs.
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The MIC4123/4124/4125 series drivers are easier to use, more
flexible in operation, and more forgiving than other CMOS
or bipolar drivers currently available. Their BiCMOS/DMOS
construction dissipates minimum power and provides rail-torail voltage swings.
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Primarily intended for driving power MOSFETs, the
MIC4123/4124/4125 drivers are suitable for driving other loads
(capacitive, resistive, or inductive) which require low-impedance, high peak currents, and fast switching times. Heavily
loaded clock lines, coaxial cables, or piezoelectric transducers
are some examples. The only known limitation on loading is
that total power dissipated in the driver must be kept within
the maximum power dissipation limits of the package.
Reliable, low-power bipolar/CMOS/DMOS construction
Latch-up protected to >200mA reverse current
Logic input withstands swing to –5V
High 3A-peak output current
Wide 4.5V to 20V operating range
Drives 1800pF capacitance in 25ns
Short <50ns typical delay time
Delay times consistent with in supply voltage change
Matched rise and fall times
TTL logic input independent of supply voltage
Low equivalent 6pF input capacitance
Low supply current
3.5mA with logic-1 input
350µA with logic-0 input
Low 2.3Ω typical output impedance
Output voltage swings within 25mV of ground or VS.
‘426/7/8-, ‘1426/7/8-, ‘4426/7/8-compatible pinout
Inverting, noninverting, and differential configurations
Exposed backside pad packaging reduces heat
ePAD SOIC-8L (θJA = 58°C/W)
4mm x 4mm MLF™-8L (θJA = 45°C/W)
Functional Diagram
VS
0.6mA
Integrated Component Count:
4 Resistors
4 Capacitors
52 Transistors
INV ERT ING
0.1mA
OUTA
INA
2kΩ
NONINV ERTING
0.6mA
INV ERT ING
0.1mA
OU TB
INB
2kΩ
NONINV ERTING
GND
Ground Unused Inputs
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
May 2005
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M9999-052405
MIC4123/4124/4125
Micrel, Inc.
Ordering Information
Part Number
Package
Configuration
Lead Finish
MIC4123YME
EPAD 8-Lead SOIC
Dual Inverting
Pb-Free
MIC4123YML
8-Lead MLF
Dual Inverting
Pb-Free
MIC4124YME
EPAD 8-Lead SOIC
Dual Non-Inverting
Pb-Free
MIC4124YML
8-Lead MLF
Dual Non-Inverting
Pb-Free
MIC4125YME
EPAD 8-Lead SOIC
Inverting + Non-Inverting
Pb-Free
MIC4125YML
8-Lead MLF
Inverting + Non-Inverting
Pb-Free
Pin & Driver Configuration
NC 1
8 NC
INA 2
7 OUTA
GND 3
MIC4124
MIC4123
MIC4123
2
A
7
4
B
5
5 OU TB
8 NC
7 OUTA
GND 3
6 VS
INB 4
NC 1
INA 2
5 OU TB
A
7
4
B
5
NC 1
8 NC
INA 2
7 OUTA
GND 3
2
A
7
4
B
5
6 VS
INB 4
5 OU TB
Inverting +
Noninverting
Dual
Noninverting
Dual
Inverting
2
6 VS
INB 4
MIC4125
MIC4125
MIC4124
Pin Description
Pin Number
Pin Name
2/4
INA / B
3
GND
6
Supply Input: Duplicate pins must be externally connected together
7/5
VS
OUTA / B
1, 8
NC
Not connected
EP
GND
M9999-052405
Function
Control Input
Ground: Duplicate pins must be externally connected together
Output: Duplicate pins must be externally connected together
Ground: Backside Pad
2
May 2005
MIC4123/4124/4125
Micrel, Inc.
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Voltage ........................................................... +24V
Input Voltage .................................. VS + 0.3V to GND – 5V
Junction Temperature ................................................150°C
Storage Temperature Range ......................–65°C to 150°C
Lead Temperature (10 sec.) ......................................300°C
ESD Susceptability, Note 3
Supply Voltage (VS) ......................................+4.5V to +20V
Junction Temperature Range .....................–40°C to 125°C
Package Thermal Resistance
4mm X 4mm MLF θJA ......................................... 45°C/W
EPAD SOIC-8L θJA ............................................. 58°C/W
MIC4123/4124/4125 Electrical Characteristics (Note 4)
4.5V ≤ VS ≤ 20V; TA = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted. Input Voltage slew rate >2.5V/µs.
Symbol
Parameter
Conditions
Min
Typ
2.4
1.5
Max
Units
Input
VIH
Logic 1 Input Voltage
VIL
Logic 0 Input Voltage
IIN
Input Current
0V ≤ VIN ≤ VS
–1
–10
VOH
High Output Voltage
IOUT = 100µA
VOL
Low Output Voltage
IOUT = –100µA
VS–0.025
RO
Output Resistance HI State
IOUT = 10mA, VS = 20V
2.3
Output Resistance LO State
IOUT = 10mA, VS = 20V
2.2
V
1.3
0.8
V
1
10
µA
µA
Output
IPK
Peak Output Current
I
Latch-Up Protection
Withstand Reverse Current
V
0.025
V
5
Ω
8
Ω
5
Ω
8
Ω
3
A
>200
mA
Switching Time
tR
Rise Time
test Figure 1, CL = 1800pF
11
35
60
ns
ns
tF
Fall Time
test Figure 1, CL = 1800pF
11
35
60
ns
ns
tD1
Delay Tlme
test Ffigure 1, CL = 1800pF
44
75
100
ns
ns
tD2
Delay Time
test Figure 1, CL = 1800pF
59
75
100
ns
ns
IS
Power Supply Current
VIN = 3.0V (both inputs)
1.5
2.5
3.5
mA
mA
IS
Power Supply Current
VIN = 0.0V (both inputs)
0.15
0.25
0.3
mA
mA
Power Supply
Note 1.
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
Devices are ESD sensitive. Handling precautions recommended. ESD tested to human body model, 1.5k in series with 100pF.
Note 4.
Specification for packaged product only.
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Micrel, Inc.
Test Circuit
VS = 20V
V S = 20V
0.1µF
A
INA
MIC4123
B
INB
INPUT
5V
90%
OUTA
1800pF
INA
OU TB
1800pF
INB
INPUT
tD1
tP W
tF
A
MIC4124
2.5V
10%
0V
VS
90%
0.1µF
4.7µF
tD2
tR
OUTA
1800pF
OUTB
1800pF
B
5V
90%
2.5V
10%
0V
VS
90%
4.7µF
tD1
tP W
tR
tD2
tF
OUTPUT
OUTPUT
10%
0V
10%
0V
Figure 1b. Non-inverting Driver Switching Time
Figure 1a. Inverting Driver Switching Time
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Micrel, Inc.
Typical Characteristic Curves
100
100
5V
12V
60
40
20
PROPAGATION DELAY (ns)
0
100
100
90
Propagation Delay
vs. Supply Voltage
td2
50
40
td1
20V
60
40
25
20
30
20
10 C
= 1000pF
LOAD
0
5
10
15
SUPPLY VOLTAGE (V)
May 2005
80
12V
0
100
1000
10000
CAPACITIVE LOAD (pF)
80
70
60
5V
20
20V
4.5
OUTPUT RESISTANCE (Ω)
120
FALL TIME (ns)
120
80
Fall Time
vs. Capactive Load
140
TIME (ns)
RISE TIME (ns)
140
Rise Time
vs. Capactive Load
15
1000
10000
CAPACITIVE LOAD (pF)
Output Resistance
vs. Supply Voltage
4.0
3.5
3.0
Output High
2.5
2.0
Output Low
1.5
1.0
0.5
0
5
10
15
INPUT VOLTAGE (V)
20
Rise and Fall Time
vs. Supply Voltage
Rise Time
Fall Time
10
5
20
0
5
CLOAD = 1000pF
10
15
SUPPLY VOLTAGE (V)
5
20
M9999-052405
MIC4123/4124/4125
Micrel, Inc.
Application Information
the driver affect the rate at which it is possible to turn a load
off: The adequacy of the grounding available for the driver,
and the inductance of the leads from the driver to the load.
The latter will be discussed in a separate section.
Although the MIC4123/24/25 drivers have been specifically
constructed to operate reliably under any practical circumstances, there are nonetheless details of usage which will
provide better operation of the device.
The E-Pad and MLF packages have an exposed pad under
the package. It's important for good thermal performance that
this pad is connected to a ground plane.
Supply Bypassing
Charging and discharging large capacitive loads quickly
requires large currents. For example, charging 2000pF from
0 to 15 volts in 20ns requires a constant current of 1.5A. In
practice, the charging current is not constant, and will usually
peak at around 3A. In order to charge the capacitor, the driver
must be capable of drawing this much current, this quickly,
from the system power supply. In turn, this means that as far
as the driver is concerned, the system power supply, as seen
by the driver, must have a VERY low impedance.
Best practice for a ground path is obviously a well laid out
ground plane. However, this is not always practical, and a
poorly-laid out ground plane can be worse than none. Attention
to the paths taken by return currents even in a ground plane
is essential. In general, the leads from the driver to its load,
the driver to the power supply, and the driver to whatever is
driving it should all be as low in resistance and inductance
as possible. Of the three paths, the ground lead from the
driver to the logic driving it is most sensitive to resistance or
inductance, and ground current from the load are what is most
likely to cause disruption. Thus, these ground paths should
be arranged so that they never share a land, or do so for as
short a distance as is practical.
As a practical matter, this means that the power supply bus
must be capacitively bypassed at the driver with at least
100X the load capacitance in order to achieve optimum
driving speed. It also implies that the bypassing capacitor
must have very low internal inductance and resistance at
all frequencies of interest. Generally, this means using two
capacitors, one a high-performance low ESR film, the other
a low internal resistance ceramic, as together the valleys in
their two impedance curves allow adequate performance over
a broad enough band to get the job done. PLEASE NOTE
that many film capacitors can be sufficiently inductive as to
be useless for this service. Likewise, many multilayer ceramic
capacitors have unacceptably high internal resistance. Use
capacitors intended for high pulse current service (in-house
we use WIMA™ film capacitors and AVX Ramguard™ ceramics; several other manufacturers of equivalent devices also
exist). The high pulse current demands of capacitive drivers
also mean that the bypass capacitors must be mounted
very close to the driver in order to prevent the effects of lead
inductance or PCB land inductance from nullifying what you
are trying to accomplish. For optimum results the sum of the
lengths of the leads and the lands from the capacitor body to
the driver body should total 2.5cm or less.
To illustrate what can happen, consider the following: The
inductance of a 2cm long land, 1.59mm (0.062") wide on a
PCB with no ground plane is approximately 45nH. Assuming a dl/dt of 0.3A/ns (which will allow a current of 3A to flow
after 10ns, and is thus slightly slow for our purposes) a voltage of 13.5 Volts will develop along this land in response to
our postulated ∆Ι. For a 1cm land, (approximately 15nH) 4.5
Volts is developed. Either way, anyone using TTL-level input
signals to the driver will find that the response of their driver
has been seriously degraded by a common ground path for
input to and output from the driver of the given dimensions.
Note that this is before accounting for any resistive drops in
the circuit. The resistive drop in a 1.59mm (0.062") land of
2oz. Copper carrying 3A will be about 4mV/cm (10mV/in) at
DC, and the resistance will increase with frequency as skin
effect comes into play.
The problem is most obvious in inverting drivers where the
input and output currents are in phase so that any attempt
to raise the driver’s input voltage (in order to turn the driver’s
load off) is countered by the voltage developed on the common ground path as the driver attempts to do what it was
supposed to. It takes very little common ground path, under
these circumstances, to alter circuit operation drastically.
Bypass capacitance, and its close mounting to the driver serves
two purposes. Not only does it allow optimum performance
from the driver, it minimizes the amount of lead length radiating at high frequency during switching, (due to the large Δ I)
thus minimizing the amount of EMI later available for system
disruption and subsequent cleanup. It should also be noted
that the actual frequency of the EMI produced by a driver is
not the clock frequency at which it is driven, but is related to
the highest rate of change of current produced during switching, a frequency generally one or two orders of magnitude
higher, and thus more difficult to filter if you let it permeate your
system. Good bypassing practice is essential to proper
operation of high speed driver ICs.
Output Lead Inductance
The same descriptions just given for PCB land inductance
apply equally well for the output leads from a driver to its load,
except that commonly the load is located much further away
from the driver than the driver’s ground bus.
Generally, the best way to treat the output lead inductance
problem, when distances greater than 4cm (2") are involved,
requires treating the output leads as a transmission line. Unfortunately, as both the output impedance of the driver and the
input impedance of the MOSFET gate are at least an order of
magnitude lower than the impedance of common coax, using
coax is seldom a cost-effective solution. A twisted pair works
about as well, is generally lower in cost, and allows use of a
Grounding
Both proper bypassing and proper grounding are necessary
for optimum driver operation. Bypassing capacitance only
allows a driver to turn the load ON. Eventually (except in rare
circumstances) it is also necessary to turn the load OFF. This
requires attention to the ground path. Two things other than
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Micrel, Inc.
wider variety of connectors. The second wire of the twisted
pair should carry common from as close as possible to the
ground pin of the driver directly to the ground terminal of the
load. Do not use a twisted pair where the second wire in the
pair is the output of the other driver, as this will not provide a
complete current path for either driver. Likewise, do not use
a twisted triad with two outputs and a common return unless
both of the loads to be driver are mounted extremely close
to each other, and you can guarantee that they will never be
switching at the same time.
is present on the input. Input voltage switching threshold is
approximately 1.5V which makes the driver directly compatible with TTL signals, or with CMOS powered from any supply
voltage between 3V and 15V.
The MIC4123/24/25 drivers can also be driven directly by
the MIC9130, MIC3808, MIC38C42, and similar switch mode
power supply ICs. By relocating the main switch drive function
into the driver rather than using the somewhat limited drive
capabilities of a PWM IC. The PWM IC runs cooler, which
generally improves its performance and longevity, and the
main switches switch faster, which reduces switching losses
and increase system efficiency.
For output leads on a printed circuit, the general rule is to make
them as short and as wide as possible. The lands should also
be treated as transmission lines: i.e., minimize sharp bends,
or narrowings in the land, as these will cause ringing. For a
rough estimate, on a 1.59mm (0.062") thick G-10 PCB a pair
of opposing lands each 2.36mm (0.093") wide translates to a
characteristic impedance of about 50Ω. Half that width suffices
on a 0.787mm (0.031") thick board. For accurate impedance
matching with a MIC4123/24/25 driver, on a 1.59mm (0.062")
board a land width of 42.75mm (1.683") would be required,
due to the low impedance of the driver and (usually) its load.
This is obviously impractical under most circumstances.
Generally the tradeoff point between lands and wires comes
when lands narrower than 3.18mm (0.125") would be required
on a 1.59mm (0.062") board.
The input protection circuitry of the MIC4123/24/25, in addition to providing 2kV or more of ESD protection, also works to
prevent latchup or logic upset due to ringing or voltage spiking
on the logic input terminal. In most CMOS devices when the
logic input rises above the power supply terminal, or descends
below the ground terminal, the device can be destroyed or
rendered inoperable until the power supply is cycled OFF
and ON. The MIC4123/24/25 drivers have been designed to
prevent this. Input voltages excursions as great as 5V below
ground will not alter the operation of the device. Input excursions above the power supply voltage will result in the excess
voltage being conducted to the power supply terminal of the
IC. Because the excess voltage is simply conducted to the
power terminal, if the input to the driver is left in a high state
when the power supply to the driver is turned off, currents as
high as 30mA can be conducted through the driver from the
input terminal to its power supply terminal. This may overload
the output of whatever is driving the driver, and may cause
other devices that share the driver’s power supply, as well as
the driver, to operate when they are assumed to be off, but
it will not harm the driver itself. Excessive input voltage will
also slow the driver down, and result in much longer internal
propagation delays within the drivers. TD2, for example, may
increase to several hundred nanoseconds. In general, while
the driver will accept this sort of misuse without damage,
proper termination of the line feeding the driver so that line
spiking and ringing are minimized, will always result in faster
and more reliable operation of the device, leave less EMI to
be filtered elsewhere, be less stressful to other components
in the circuit, and leave less chance of unintended modes of
operation.
To obtain minimum delay between the driver and the load, it
is considered best to locate the driver as close as possible to
the load (using adequate bypassing). Using matching transformers at both ends of a piece of coax, or several matched
lengths of coax between the driver and the load, works in
theory, but is not optimum.
Driving at Controlled Rates
Occasionally there are situations where a controlled rise or
fall time (which may be considerably longer than the normal
rise or fall time of the driver’s output) is desired for a load. In
such cases it is still prudent to employ best possible practice
in terms of bypassing, grounding and PCB layout, and then
reduce the switching speed of the load (NOT the driver) by
adding a noninductive series resistor of appropriate value
between the output of the driver and the load. For situations
where only rise or only fall should be slowed, the resistor can
be paralleled with a fast diode so that switching in the other
direction remains fast. Due to the Schmitt-trigger action of the
driver’s input it is not possible to slow the rate of rise (or fall)
of the driver’s input signal to achieve slowing of the output.
Power Dissipation
CMOS circuits usually permit the user to ignore power dissipation. Logic families such as 4000 series and 74Cxxx have
outputs which can only source or sink a few milliamps of current, and even shorting the output of the device to ground or
VCC may not damage the device. CMOS drivers, on the other
hand, are intended to source or sink several Amps of current.
This is necessary in order to drive large capacitive loads at
frequencies into the megahertz range. Package power dissipation of driver ICs can easily be exceeded when driving
large loads at high frequencies. Care must therefore be paid
to device dissipation when operating in this domain.
Input Stage
The input stage of the MIC4123/24/25 consists of a singleMOSFET class A stage with an input capacitance of <8pF.
This capacitance represents the maximum load from the
driver that will be seen by its controlling logic. The drain load
on the input MOSFET is a –2mA current source. Thus, the
quiescent current drawn by the driver varies, depending upon
the logic state of the input.
Following the input stage is a buffer stage which provides
~400mV of hysteresis for the input, to prevent oscillations
when slowly-changing input signals are used or when noise
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PL1 = I RO D
The Supply Current vs Frequency and Supply Current vs
Load characteristic curves furnished with this data sheet
aid in estimating power dissipation in the driver. Operating
frequency, power supply voltage, and load all affect power
dissipation.
2
However, in this instance the RO required may be either the on
resistance of the driver when its output is in the high state, or
its on resistance when the driver is in the low state, depending
upon how the inductor is connected, and this is still only half
the story. For the part of the cycle when the inductor is forcing
current through the driver, dissipation is best described as
Given the power dissipation in the device, and the thermal
resistance of the package, junction operating temperature
for any ambient is easy to calculate. For example, the
thermal resistance of the 8-pin E-Pas SOIC package, from
the datasheet, is 58°C/W. In a 25°C ambient, then, using a
maximum junction temperature of 150°C, this package will
dissipate 2.16W.
PL2 = I VD (1 – D)
where VD is the forward drop of the clamp diode in the driver
(generally around 0.7V). The two parts of the load dissipation
must be summed in to produce PL
Accurate power dissipation numbers can be obtained by summing the three sources of power dissipation in the device:
PL = PL1 + PL2
Quiescent Power Dissipation
Quiescent power dissipation (PQ, as described in the input
section) depends on whether the input is high or low. A low
input will result in a maximum current drain (per driver) of
≤0.2mA; a logic high will result in a current drain of ≤2.0mA.
Quiescent power can therefore be found from:
• Load power dissipation (PL)
• Quiescent power dissipation (PQ)
• Transition power dissipation (PT)
Calculation of load power dissipation differs depending upon
whether the load is capacitive, resistive or inductive.
PQ = VS [D IH + (1 – D) IL]
Resistive Load Power Dissipation
Dissipation caused by a resistive load can be calculated as:
where:
PL = I RO D
2
IH =
IL =
D=
VS =
where:
I = the current drawn by the load
RO = the output resistance of the driver when the
output is high, at the power supply voltage used
(See characteristic curves)
D = fraction of time the load is conducting (duty cycle)
Transition Power Dissipation
Transition power is dissipated in the driver each time its
output changes state, because during the transition, for a
very brief interval, both the N- and P-channel MOSFETs in
the output totem-pole are ON simultaneously, and a current
is conducted through them from VS to ground. The transition
power dissipation is approximately:
Capacitive Load Power Dissipation
Dissipation caused by a capacitive load is simply the energy
placed in, or removed from, the load capacitance by the
driver. The energy stored in a capacitor is described by the
equation:
PT = f VS (A•s)
where (A•s) is a time-current factor derived from Figure 2.
E = 1/2 C V2
Total power (PD) then, as previously described is just
As this energy is lost in the driver each time the load is charged
or discharged, for power dissipation calculations the 1/2 is
removed. This equation also shows that it is good practice
not to place more voltage in the capacitor than is necessary,
as dissipation increases as the square of the voltage applied
to the capacitor. For a driver with a capacitive load:
PD = PL + PQ +PT
Examples show the relative magnitude for each term.
EXAMPLE 1: A MIC4123 operating on a 12V supply driving
two capacitive loads of 3000pF each, operating at 250kHz,
with a duty cycle of 50%, in a maximum ambient of 60°C.
PL = f C (VS)2
First calculate load power loss:
where:
PL = f x C x (VS)2
PL = 250,000 x (3 x 10–9 + 3 x 10–9) x 122
= 0.2160W
f = Operating Frequency
C = Load Capacitance
VS = Driver Supply Voltage
Then transition power loss:
Inductive Load Power Dissipation
For inductive loads the situation is more complicated. For
the part of the cycle in which the driver is actively forcing
current into the inductor, the situation is the same as it is in
the resistive case:
May 2005
quiescent current with input high
quiescent current with input low
fraction of time input is high (duty cycle)
power supply voltage
PT = f x VS x (A•s)
= 250,000 • 12 • 2.2 x 10–9 = 6.6mW
Then quiescent power loss:
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In a MLF with an θJA of 60°C/W, this amount of power results
in a junction temperature given the maximum 40°C ambient
of:
PQ = VS x [D x IH + (1 – D) x IL]
= 12 x [(0.5 x 0.0035) + (0.5 x 0.0003)]
= 0.0228W
Total power dissipation, then, is:
(0.213 x 100) + 40 = 52.8°C
PD = 0.2160 + 0.0066 + 0.0228
= 0.2454W
The actual junction temperature will be lower than calculated
both because duty cycle is less than 100% and because the
graph lists RDS(on) at a TJ of 125°C and the RDS(on) at 52.8°C TJ
will be somewhat lower.
Assuming an E-Pad SOIC package, with an θJA of 58°C/W,
this will result in the junction running at:
Definitions
CL = Load Capacitance in Farads.
0.2454 x 58 = 14.2°C
above ambient, which, given a maximum ambient temperature of 60°C, will result in a maximum junction temperature
of 89.4°C.
D = Duty Cycle expressed as the fraction of time the
input
to the driver is high.
f = Operating Frequency of the driver in Hertz.
EXAMPLE 2: A MIC4124 operating on a 15V input, with one
driver driving a 50Ω resistive load at 1MHz, with a duty cycle
of 67%, and the other driver quiescent, in a maximum ambient temperature of 40°C:
IH = Power supply current drawn by a driver when both
inputs are high and neither output is loaded.
IL = Power supply current drawn by a driver when both
inputs are low and neither output is loaded.
PL = I2 x RO x D
First, IO must be determined.
ID = Output current from a driver in Amps.
IO = VS / (RO + RLOAD)
PD = Total power dissipated in a driver in Watts.
Given RO from the characteristic curves then,
PL = Power dissipated in the driver due to the driver’s
load
in Watts.
IO = 15 / (3.3 + 50)
IO = 0.281A
PQ = Power dissipated in a quiescent driver in Watts.
and:
PT = Power dissipated in a driver when the output
changes
states (“shoot-through current”) in Watts.
NOTE: The “shoot-through” current from a dual
transition (once up, once down) for both drivers is
stated in the graph on the following page in amperenanoseconds. This figure must be multiplied by the
number of repetitions per second (frequency to find
Watts).
RO = Output resistance of a driver in Ohms.
PL = (0.281)2 x 3.3 x 0.67
= 0.174W
PT = F x VS x (A•s)/2
(because only one side is operating)
= (1,000,000 x 15 x 3.3 x 10–9) / 2
= 0.025 W
and:
PQ = 15 x [(0.67 x 0.00125) + (0.33 x 0.000125) +
(1 x 0.000125)]
VS = Power supply voltage to the IC in Volts.
(this assumes that the unused side of the driver has its input
grounded, which is more efficient)
= 0.015W
then:
PD = 0.174 + 0.025 + 0.0150
= 0.213W
M9999-052405
9
May 2005
MIC4123/4124/4125
Micrel, Inc.
C ros s over
E nergy L os s
A•s (Ampere-seconds)
10 -8
10 -9
10 -10
0
2
4
6
8 10 12 14 16 18 20
V IN
NOTE: THE VALUES ON THIS GRAPH REPRESENT THE LOSS SEEN BY BOTH
DRIVERS IN A PACKAGE DURING ONE COMPLETE CYCLE. FOR A SINGLE
DRIVER DIVIDE THE STATED VALUES BY 2. FOR A SINGLE TRANSITION OF A
SINGLE DRIVER, DIVIDE THE STATED VALUE BY 4.
Figure 2.
May 2005
10
M9999-052405
MIC4123/4124/4125
Micrel, Inc.
Package Information
A
A1
D
A2
D1
5
A3
DIMENSION
(mm)
NOM.
N
1
2
3
E1
E
0
TOP VIEW
4X P
SEATING
PLANE
PIN1 ID
0.20 R.
D2
1
N
0.85
0.01
0.65
0.20 REF.
4.00 BSC
3.75 BSC
2.40
4.00 BSC
3.75 BSC
3.20
0.00
-
2.25
3.05
0.42
0.65 BSC
8
0.45
0.28
0.24
0.30
0.23
MAX.
1.00
0.05
0.80
2.55
3.35
12°
0.60
0.60
0.35
NOTE:
1. ALL DIMENSIONS ARE IN MILLIMETERS .
2. N IS THE NUMBER OF TERMINALS .
THE NUMBER OF TERMINALS PER SIDE IS N/4.
3. THE PIN#1 IDENTIFIRE MUST BE EXISTED ON THE TOP SURFACE
OF PACKAGE BY USING IDENTIFI CATION MARK OR OTHER
FEATURE OF PACKAGE BODY.
4. PACKAGE WARPAGE MAX 0.05mm.
4X P
2
e
A
A1
A2
A3
D
D1
D2
E
E1
E2
0
P
e
N
L
b
MIN.
3
E2
5. APPLIED FOR EXPOSED PAD AND TERMINALS .
b
L
BOTTOM VIEW
8-Pin 4x4 MLF (ML)
8-Pin Exposed Pad SOIC (ME)
MICREL INC.
TEL
2180 FORTUNE DRIVE
+ 1 (408) 944-0800
FAX
SAN JOSE, CA 95131
+ 1 (408) 474-1000
WEB
USA
http://www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's
use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2004 Micrel Incorporated
M9999-052405
11
May 2005