ETC ZXRD1050PQ16TA

ZXRD1000 SERIES
PWM DC-DC CONTROLLERS
HIGH EFFICIENCY SIMPLESYNC
DESCRIPTION
ZXRD1000 series can be used with an all N channel
topology or a combination N & P channel topology.
Additional functionality includes shutdown control, a
user adjustable low battery flag and simple
adjustment of the fixed PWM switching frequency.
The controller is available with fixed outputs of 5V or
3.3V and an adjustable (2.0 to 12V) output.
The ZXRD1000 series provides complete control and
protection functions for a high efficiency (> 95%) DC-DC
converter solution. The choice of external MOSFETs allow
the designer to size devices according to application. The
ZXRD1000 series uses advanced DC-DC converter
techniques to provide synchronous drive capability, using
innovative circuits that allow easy and cost effective
implementation of shoot through protection. The
FEATURES
> 95% Efficiency
Fixed frequency (adjustable) PWM
Voltage mode to ensure excellent stability &
transient response
Fixed 3.3, 5V and adjustable outputs
Programmable soft start
APPLICATIONS
Low quiescent current in shutdown mode,15A
Low battery flag
Output down to 2.0V
Overload protection
Demonstration boards available
Synchronous or non-synchronous operation
Cost effective solution
N or P channel MOSFETs
QSOP16 package
High efficiency 5 to 3.3V converters up to 4A
Sub-notebook computers
Embedded processor power supply
Distributed power supply
Portable instruments
Local on card conversion
GPS systems
Very high efficiency SimpleSyncTM converter.
VCC
4.5-10V
D2
BAT54
IC1
R1
100k
9
Shut Down
C5
13
VIN
LBSET
ZXM64N02X
Bootstrap
N1
C10
VDRIVE 2
SHDN
L1
15µH
1µF
C11
1µF
1
1µF
Low input flag
11 LBF
RSENSE+ 7
14
10
6
5
RSENSE - 8
Delay
Decoup
VINT
CT
GND
CIN
68µF
C1
1µF
C2
330pF
4
1µF
C4
VFB 16
Comp
15
PWR
GND
R6
10k
C6
1µF
C8
D1
D3
BAT54
N2
ZXM64N02X
R3
3k
ISSUE 3 - MAY 2000
Cx2
0.01µF
COUT
Fx
RX
R2 CX1
2k7
680R 0.022µF
R4
10k
3
C7
22µF
1µF C3
VOUT
3.3V 4A
RSENSE
0.01R
1
2.2µF
ZHCS1000
R5
6k
x2
680µF
C9
1µF
120µF
ZXRD1000 SERIES
ABSOLUTE MAXIMUM RATINGS
Input without bootstrap (P suffix)
Input with bootstrap(N suffix)
Bootstrap voltage
20V
Shutdown pin
VIN
LBSET pin
VIN
20V
10V
RSENSE+, RSENSE Power dissipation
Operating temperature
Storage temperature
VIN
610mW (Note 4)
-40 to +85°C
-55 to +125°C
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS (Unless otherwise stated) Tamb=25°C
Symbol
Parameter
Conditions
Min
V IN(min)
Min. Operating Voltage
No Output Device
4.5
V FB
(Note 1)
Feedback Voltage
V IN =5V,I FB =1mA
4.5<V IN <18V
T DRIVE
I CC
Unit
1.215
1.24
1.265
V
V
1.213
1.24
1.267
V
1.24
1.265
V
Gate Output Drive Capability
C G =2200pF(Note 2)
C G =1000pF
V IN =4.5V to maximim
supply (Note 3)
60
35
Supply Current
V IN =5V
16
20
mA
Shutdown Current
V SHDN = 0V;V IN =5V
15
50
A
300
kHz
25
%
94
100
%
%
Operating frequency range
Frequency with timing capacitor C3=1300pF
C 3 =330pF
f osc(tol)
Oscillator Tol.
DC
Max Duty Cycle
N Channel
P Channel
R SENSE voltage differential
-40 to +85°C
V RSENSE
Max
50 A<I FB <1mA,V IN =5V 1.215
f osc
(Note 5)
MAX
Typ
V CMRSENSE Common mode range of V RSENSE
LBF SET
Low Battery Flag set voltage
LBF OUT
Low Battery Flag output
LBF HYST
Low Battery Flag Hysteresis
LBF SINK
Low Battery Flag Sink Current
V SHDN
Shutdown Threshold Voltage
I SHDN
Shutdown Pin Source Current
-40 to +85°C
50
ns
ns
50
200
15
0
50
2
mV
V IN
1.5
V
V IN
V
0.2
0.4
V
20
50
mV
-40 to +85°C
2
mA
Low(off)
High(on)
0.25
V
V
Active Low
10
1.5
10
A
Note 1. VFB has a different function between fixed and adjustable controller options.
Note 2. 2200pF is the maximum recommended gate capacitance.
Note 3. Maximum supply for P phase controllers is 18V,maximum supply for N phase controllers is 10V.
Note 4. See VIN derating graph in Typical Characteristics.
Note 5. The maximum frequency in this application is 300kHz. For higher frequency operation contact Zetex
Applications Department.
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ISSUE 3 - MAY 2000
ZXRD1000 SERIES
TYPICAL CHARACTERISTICS
202
C3=330pF
VIN=5V
210
C3=330pF
FOSC (kHz)
FOSC (kHz)
201
200
199
205
200
195
198
190
197
4
6
8
10
12
14
16
18
20
-40
-20
0
VIN (V)
20
40
60
80
100
80
100
Temperature (°C)
FOSC v VIN
FOSC v Temperature
VOUT=3.3V
1.244
1.25
1.242
1.245
VIN=5V
VFB (V)
VFB (V)
VOUT=3.3V
1.24
1.24
1.238
1.235
1.236
1.23
4
6
8
10
12
14
16
18
20
-40
-20
VIN (V)
0
20
40
60
Temperature (°C)
VFB v VIN
VFB v Temperature
1.02
VIN=5V
Normalised LBSET
Normalised LBSET
1.005
1.01
1.00
1.000
0.995
0.99
4
6
8
10
12
14
16
18
20
-40
VIN (V)
0
20
40
60
80
100
Temperature (°C)
Normalised LBSET v VIN
ISSUE 3 - MAY 2000
-20
Normalised LBSET v Temperature
3
ZXRD1000 SERIES
30
30
Supply Current (mA)
Supply Current (mA)
TYPICAL CHARACTERISTICS
25
20
15
10
25
20
15
10
4
6
8
10
12
14
16
18
20
4
6
8
10
12
14
16
VIN (V)
VIN (V)
Supply Current v VIN
N Phase Device
Supply Current v VIN
P Phase Device
18
20
5
Current Limit (A)
Vin=5V
FOSC (kHz)
300
200
100
4
3
2
VIN=5V
1
0
100pF
VOUT=3.3V
0
1nF
0
10nF
Timing Capacitance
10
20
30
40
50
RSENSE (m⍀)
FOSC v Capacitance
Current Limit v RSENSE
CG=2200pF
VIN (V)
20
15
10
5
-40
-20
0
20
40
60
80
100
Temperature (°C)
VIN Derating v Temperature
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ISSUE 3 - MAY 2000
ZXRD1000 SERIES
DETAILED DESCRIPTION
systems this can not only damage MOSFETs, but also
the battery itself. To realise correct ‘dead time’
implementation takes complex circuitry and hence
implies additional cost.
The ZXRD1000 series can be configured to use either
N or P channel MOSFETs to suit most applications.
The most popular format, an a ll N channel
synchronous solution gives the optimum efficiency. A
feature of the ZXRD1000 series solution is the unique
method of generating the synchronous drive, called
SimpleSync . Most solutions use an additional
output from the controller, inverted and delayed from
the main switch drive. The ZXRD1000 series solution
uses a simple overwinding on the main choke (wound
on the same core at no real cost penalty) plus a small
ferrite bead . This means that the synchronous FET is
only enhanced when the main FET is turned off. This
reduces the ‘blanking period’ required for shootthrough protection, increasing efficiency and allowing
smaller catch diodes to be used, making the controller
simpler and less costly by avoiding complex timing
circuitry. Included on chip are numerous functions that
allow flexibility to suit most applications. The nominal
switching frequency (200kHz) can be adjusted by a
simple timing capacitor, C3. A low battery detect circuit
is also provided. Off the shelf components are available
from major manufacturers such as Sumida to provide
either a single winding inductor for non-synchronous
applications or a coil with an over-winding for
synchronous applications. The combination of these
switching characteristics, innovative circuit design and
excellent user flexibility, make the ZXRD1000 series
DC-DC solutions some of the smallest and most cost
effective and electrically efficient currently available.
Using Zetex’s HDMOS low RDS(on) devices, ZXM64N02X
for the main and synchronous switch, efficiency can
peak at upto 95% and remains high over a wide range
of operating currents. Programmable soft start can also be
adjusted via the capacitor, C7, in the compensation loop.
The ZETEX Method
Zetex has taken a different approach to solving these
problems. By looking at the basic architecture of a
synchronous converter, a novel approach using the
main circuit inductor was developed. By taking the
inverse waveform found at the input to the main
i n d u c to r o f a n o n - sy n ch r o n o u s so l u t i on , a
synchronous drive waveform can be generated that is
always relative to the main drive waveform and
inverted with a small delay. This waveform can be
used to drive the synchronous switch which means no
complex circuitry in the IC need be used to allow for
shoot-through protection.
Implementation
Implementation was very easy and low cost. It simply
meant peeling off a strand of the main inductor
winding and isolating it to form a coupled secondary
winding. These are available as standard items
referred to in the applications circuits parts list.The use
of a small, surface mount, inexpensive ’square loop’
ferrite bead provides an excellent method of
eliminating shoot-through due to variation in gate
thresholds. The bead essentially acts as a high
i mp e da n ce fo r the few na n o seco nd s that
shoot-through would normally occur. It saturates very
quickly as the MOSFETs attain steady state operation,
reducing the bead impedance to virtually zero.
Benefits
The net result is an innovative solution that gives
a d d i ti o n a l b e n e fi ts wh il st lo we r in g o v e ra l l
implementation costs. It is also a technique that can
be simply omitted to make a non-synchronous
controller, saving further cost, at the expense of a few
efficiency points.
What is SimpleSyncTM?
Conventional Methods
In the conventional approach to the synchronous
DC-DC solution, much care has to be taken with the
timing constraints between the main and synchronous
switching devices. Not only is this dependent upon
individual MOSFET gate thresholds (which vary from
device to device within data sheet limits and over
temperature), but it is also somewhat dependent upon
magnetics, layout and other parasitics. This normally
means that significant ‘dead time’ has to be factored
in to the design between the main and synchronous
devices being turned off and on respectively.
Incorrect application of dead time constraints can
potentially lead to catastrophic short circuit conditions
between VIN and GND. For some battery operated
ISSUE 3 - MAY 2000
5
ZXRD1000 SERIES
Functional Block Diagram
PIN DESCRIPTIONS
‡ See relevant Applications Section
Pin No.
Name
1
Bootstrap Bootstrap circuit for generating gate drive
Description
2
V DRIVE
Output to the gate drive circuit for main N/P channel switches
3
PWRG ND
Power ground
4
G ND
Signal ground
5
CT
Timing Capacitor sets oscillator frequency. ‡
6
V INT
Internal Bias Circuit. Decouple with 1 F ceramic capacitor
7
R SENSE+
Higher potential input to the current sense for current limit circuit
8
R SENSE-
Lower potential input to the current sense for current limit circuit
9
SHDN
Shutdown control. Active low.
10
Decoup
Optional short circuit and overload decoupling capacitor for increased accuracy
11
LBF
Low battery flag output. Active low, open collector output
12
LB SET
Low battery flag set. Can be connected to VIN if unused, or threshold set
via potential divider. ‡
13
V IN
Input Voltage
14
Delay
External R and C to set the desired cycle time for hiccup circuit. ‡
15
Comp
Compensation pin to allow for stability components and soft start. ‡
16
V FB
Feedback Voltage. This pin has a different function between fixed and
adjustable controller options. The appropriate controller must be used for
the fixed or adjustable solution. Connect to VOUT for fixed output, or to
potential divider for adjustable output. ‡
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ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Applications
Input Capacitors
Note: Component names refer to designators shown
in the application circuit diagrams.
The input capacitor is chosen for its RMS current and
voltage rating. The use of low ESR electrolytic or
tantalum capacitors is recommended. Tantalum
capacitors should have their voltage rating at 2VIN
(max), electrolytic at 1.4VIN(max). IRMS can be
approximated by:
Output Capacitors
Output capacitors are a critical choice in the overall
performance of the solution. They are required to filter
the output and supply load transient current. They are
also affected by the switching frequency, ripple
current, di/dt and magnitude of transient load current.
ESR plays a key role in determining the value of
capacitor to be used. Combination of both high
frequency, low value ceramic capacitors and low ESR
bulk storage capacitors optimised for switching
applications provide the best response to load
transients and ripple requirements. Electrolytic
capacitors with low ESR are larger and more
expensive so the ultimate choice is always a
compromise between size, cost and performance.
Care must also be taken to ensure that for large
capacitors, the ESL of the leads does not become an
issue. Excellent low ESR tantalum or electrolytic
capacitors are available from Sanyo OS-CON, AVX,
Sprague and Nichicon.
IRMS IOUT
Also note that the input capacitance ESR is effectively in
series with the input and hence contributes to efficiency
losses related to IRMS2 * ESR of the input capacitor.
MOSFET Selection
The ZXRD1000 family can be configured in circuits
where either N or P channel MOSFETs are employed
as the main switch. If an N channel device is used, the
corresponding N phase controller must be chosen.
Similarly, for P channel main switch a P phase
controller must be used. The ordering information has
a clear identifier to distinguish between N and P phase
controllers.
The MOSFET selection is subject to thermal and gate
drive considerations. Care also has to be taken to allow
for transition losses at high input voltages as well as
RDS(ON) l o ss e s f o r t h e m a i n MO SF ET . I t is
recommended that a device with a drain source
breakdown of at least 1.2 times the maximum VIN
should be used.
0.29 VOUT VINVOUT
L f VIN
where L= output filter inductance
f= switching frequency
For output voltage ripple it is necessary to know the
peak ripple current which is given by:
Ipkpk VIN
Underspecification of this parameter can affect long
term reliability. An additonal ceramic capacitor should
be used to provide high frequency decoupling at VIN.
The output capacitor will also affect loop stability,
transient performance. The capacitor ESR should
preferably be of a similar value to the sense resistor.
Parallel devices may be required.
IRIPPLERMS VOUTVINVOUT
For optimum efficiency , two N channel low RDS(on)
devices are required. MOSFETs should be selected
with the lowest RDS(ON) consistent with the output
current required. As a guide, for 3-4A output, <50m
devices would be optimum, provided the devices are
low gate threshold and low gate charge. Typically look
for devices that will be fully enhanced with 2.7V VGS
for 4-5A capability.
VOUT VIN VOUT
L f VIN
Voltage ripple is then:VRIPPLE Ipk pk ESR
Zetex offers a range of low RDS(ON) logic level MOSFETs
which are specifically designed with DC-DC power
conversion in mind. Packaging includes SOT23,
SOT23-6 and MSOP8 options. Ideal examples of
optimum devices would be Zetex ZXM64N03X and
ZXM64N02X (N channel). Contact your local Zetex office
or Zetex web page for further information.
ISSUE 3 - MAY 2000
7
ZXRD1000 SERIES
Applications (continued)
Inductor Selection
conditions, when VIN is at its highest and VOUT is
lowest (short circuit conditions for example). Under
these conditions the device must handle peak current
at close to 100% duty cycle.
The inductor is one of the most critical components in
the DC-DC circuit.There are numerous types of devices
available from many suppliers. Zetex has opted to
specify off the shelf encapsulated surface mount
components, as these represent the best compromise
in terms of cost, size, performance and shielding.
Frequency Adjustment
The nominal running frequency of the controller is set
to 200kHz in the applications shown. This can be
adjusted over the range 50kHz to 300kHz by changing
the value of capacitor on the CT pin. A low cost
ceramic capacitor can be used.
Frequency = 60000/C3 (pF)
Frequency v temperature is given in the typical
characteristics.
The SimpleSyncTM technique uses a main inductor
with an overwinding for the gate drive which is
available as a standard part. However, for engineers
who wish to design their own custom magnetics, this
is a relatively simple and low cost construction
technique. It is simply formed by terminating one of
the multiple strands of litz type wire separately. It is
still wound on the same core as the main winding and
only has to handle enough current to charge the gate
of the synchronous MOSFET. The major benefit is
circuit simplification and hence lower cost of the control
IC. For non-synchronous operation, the overwinding is
not required.
Output Voltage Adjustment
The ZXRD1000 is available as either a fixed 5V, 3.3V or
adjustable output. On fixed output versions, the VFB pin
should be connected to the output. Adjustable operation
requires a resistive divider connected as follows:
The choice of core type also plays a key role. For
optimum performance, a ’swinging choke’ is often
preferred. This is one which exhibits an increase in
inductance as load current decreases. This has the net
effect of reducing circulating current at lighter load
improving efficiency. There is normally a cost
premium for this added benefit. For this reason the
chokes specified are the more usual constant
inductance type.
Peak current of the inductor should be rated to
minimum 1.2IOUT (max) . To maximise efficiency, the
winding resistance of the main inductor should be less
than the main switch output on resistance.
The value of the output voltage is determined by the
equation
Schottky Diode
VOUT VFB 1 Selection depends on whether a synchronous or
non-synchronous approach is taken. For the
ZXRD1000, the unique approach to the synchronous
drive means minimal dead time and hence a small
SOT23 1A DC rated device will suffice, such as the
ZHCS1000 from Zetex. The device is only designed to
prevent the body diode of the synchronous MOSFET
from conducting during the initial switching transient
until the MOSFET takes over. The device should be
connected as close as possible to the source terminals
of the main MOSFET.
RA
RB
VFB 1.24V
Note: The adjustable circuit is shown in the following
transient optimisation section. It is also used in the
evaluation PCB. In both these circuits RA is assigned
the label R6 and RB the label R5.
Values of resistor should be between 1k and 20k to
guarantee operation. Output voltage can be adjusted in
the range 2V to 12V for non-synchronous applications.
For synchronous applications, the minimum VOUT is set
by the VGS threshold required for the synchronous
MOSFET, as the swing in the gate using the
SimpleSyncTM technique is approximately VOUT.
For non-synchronous applications , the Schottky diode
must be selected to allow for the worst case
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ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Applications (continued)
Low Battery Flag
Hiccup Time Constant
The low battery flag threshold can be set by the user
to trip at a level determined by the equation:
The hiccup circuit (at the ’delay’ pin) provides overload
protection for the solution. The threshold of the hiccup
mode is determined by the value of RSENSE, When
>50mV is developed across the sense resistor, the
hiccup circuit is triggered, inhibiting the device.
VLBSET 1.25 1 RC
RD
RD is recommended to be 10k where RC and RD are
connected as follows:
It will stay in this state depending upon the time
constant of the resistor and capacitor connected at the
’delay’ pin. In order to keep the dissipation down
under overload conditions it is recommended the
circuit be off for approximately 100ms. If for other
application reasons this is too long an off period, this
can be reduced at least by 10:1, care needs to be taken
that any increased dissipation in the external MOSFET
is still acceptable. The resistor capacitor combination
R1,C1 recommended in the applications circuits
provides a delay of 100ms.
Soft Start & Loop Stability
Soft start is determined by the time constant of the
capacitor and resistor C7 and R3. Typically a good
starting point is C7 = 22F and R3 = 24k for fixed
voltage variants. For fully adjustable variants see
Optimising for Transient Response later in the
applications section. This network also helps provide
good loop stability.
Hysteresis is typically 20mV at the LBSET pin.
Current Limit
A current limit is set by the low value resistor in the
output path, RSENSE. Since the resistor is only used for
overload current limit, it does not need to be accurate
and can hence be a low cost device.
Low Quiescent Shutdown
Shutdown control is provided via the SHDN pin,
putting the device in to a low quiescent sleep mode.
In some circumstances where rapid sequencing of VCC
can occur (when VCC is turned off and back on) and VCC
has a very rapid rise time (100-200ms) timing conflicts
can occur.
The value of the current limit is set by using the
equation:
ILIM A 50mV
RSENSEm
A graph of Current Limit v RSENSE is shown in the
typical characteristics. This should assist in the
selection of RSENSE appropriate to application.
If desired, RSENSE can also be on the input supply side.
When used on the input side RSENSE should be in series
with the upper output device (i.e. in series with the
drain or source in N and P channel solutions
respectively).Typically in this configuration RSENSE will
be 20m⍀.
ISSUE 3 - MAY 2000
9
ZXRD1000 SERIES
Optimising for Transient Response.
Layout Issues
Transient response is important in applications where
the load current increases and decreases rapidly. To
optimise the system for good transient response
certain criteria have to be observed.
Layout is critical for the circuit to function in the most
efficient manner in terms of electrical efficiency,
thermal considerations and noise. The following
guidelines should be observed:
The optimum solution using the ZXRD series uses the
adjustable N phase controller in synchronous mode as
represented in the diagram opposite. The external
networks for this solution require the use of the
adjustable controller option.
A 2.2F (C8) decoupling capacitor should be as close
as possible to the drive MOSFETs and D1 anode. This
capacitor is effectively connected across VIN and GND
but should be as close as possible to the appropriate
components in either N or P, synchronous or
non-synchronous configurations. Furthermore the
GND connection of the synchronous MOSFET/D1 and
output capacitors should be close together and use
either a ground plane or at the very least a low
inductance PCB track.
By using standard ’bulk’ capacitors in parallel with a
single OS-CON capacitor significant performance
versus cost advantage can be given in this application.
The low ESR of the OS-CON capacitor provides
competitive output voltage ripple at low capacitance
values. The ’bulk’ capacitors aid transient response.
However, the low ESR of the OS-CON capacitor can
cause instability within the system. To maintain
stability an RC network (RX, Cx1 ) ha s to be
implemented. Furthermore, a capacitor in parallel with
R6 (Cx2) is required to optimise transient response. To
do this the appropriate adjustable ZXRD must be used
because the input to the internal error amplifier (pin
16) has to be accessed. The adjustable device differs
from fixed controller versions in this respect. This
combined with a frequency compensation adjustment
gives an optimised solution for excellent transient
response.
For the standard application circuits, a Gerber file can
be made available for the layout which uses the
materials as listed in the bill of materials table for the
reference designs.
Reference Designs.
In the following section reference circuits are shown for
the ZXRD se ries in both synchronous and
non-synchronous modes. These are shown for each of
the N and P phase controllers. In each case efficiency
graphs are shown for the appropriate configuration
using 3.3V and 5V ZXRD devices. The BOM is then
shown for the design. Additional and alternative
components are shown with a ’*’. These refer to
modifications to the design to optimise for transient
response. Optimisation is reached using the adjustable
version of either N or P phase controller device.
10
ISSUE 3 - MAY 2000
VCC
ISSUE 3 - MAY 2000
11
1µF
C1
1µF
C5
330pF
1µF C3
C2
R1
100k
LBSET
SHDN
1µF
C4
14
10
6
5
R3
3k
4
GND
Delay
Decoup
VINT
CT
11 LBF
9
IC1
8
7
1
2
3
C7
22µF
16
VFB
Comp
15
PWR
GND
RSENSE -
RSENSE+
Bootstrap
VDRIVE
13
VIN
RX
R2 CX1
2k7
680R 0.022µF
C6
1µF
1µF
C10
R4
10k
Fx
N2
ZXM64N02X
D3
BAT54
C11
1µF
ZXM64N02X
D2
BAT54
D1
N1
ZHCS1000
2.2µF
C8
L1
15µH
0.01R
RSENSE
R5
6k
R6
10k
TM
Optimised Transient Response, 4.5V-10V Input, 3V/4A Output, N Phase Adjustable, SimpleSync
CIN
68µF
Low input flag
Shut Down
4.5-10V
Cx2
120µF
COUT
C9
1µF
converter 200kHz.
x2
680µF
0.01µF
VOUT
3.3V 4A
ZXRD1000 SERIES
ZXRD1000 SERIES
4.5V -10VInput, 3.3V/4A Output, N Phase, High Efficiency SimpleSyncTM Converter
200kHz
VCC
4.5-10V
D2
R1
13
IC1
9
Shut Down
VIN
Bootstrap
LBSET
C5
11 LBF
Low input flag
RSENSE+
14
10 Delay
6 Decoup
V
5 INT
CT
GND
CIN
4
C1
C2
C3
N1
VDRIVE
SHDN
C4
RSENSE -
C10
2
L1
C11
1
VOUT
3.3V 4A
RSENSE
7
C6
8
16
VF B
Comp 15
PWR
GND
N2
R4
3
C9
Fx
R2
D1
C8
D3
COUT
C7
R3
ZXRD1033NQ16
100
VIN=7V
95
90
VIN=10V
Efficiency (%)
85
80
75
70
65
Efficiency v IOUT
VOUT=5.0V.
60
55
50
0.1
1
IOUT (A)
12
ZXRD1050NQ16
10
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Ref
Part Number
Manufacturer
Comments
IC1
Value
ZXRD1033NQ16
Zetex
QSOP16 Controller IC
N1
V IN >7V
V IN <7V
N2
Zetex
ZXM64N03X
ZXM64N02X
ZXM64N02X
MSOP8 Low RDS(ON)
N MOSFET
30V V DS
20V V DS
20V V DS
D1
1A 0.5V V F
ZHCS1000
Zetex
SOT23 Schottky Diode 1A
D2
10mA 0.4V V F
BAT54
Zetex
SOT23 Schottky Diode
D3
10mA 0.4V V F
BAT54
Zetex
SOT23 Schottky Diode
R1
100k
WCR0805-100k
Welwyn/IRC
0805 Size
R2
680⍀
WCR0805-680
Welwyn/IRC
0805 Size
0805 Size
R3
24k
WCR0805-24k
Welwyn/IRC
*R3
3k
WCR0805-3k
Welwyn/IRC
0805 Size
R4
10k
WCR0805-10k
Welwyn/IRC
0805 Size
*Rx
2.7K
WCR0805-2.7k
Welwyn/IRC
0805 Size
R SENSE
0.01⍀
LR1206R010
Welwyn/IRC
Current Limit Sense Resistor
C IN
68␮F
68␮F
68␮F
TPSD68M016R0150
20SA68M
20SV68M
AVX
Sanyo OS-CON
Sanyo OS-CON
68␮F 16V ’E’ low ESR
68␮F 20V PTH low ESR
68␮F 20V SMT low ESR
C OUT
OR
OR
470␮F
*150␮F
*120␮F
TPSE477M010R0200 AVX
6SA150M
Sanyo OS-CON
6SV120M
Sanyo OS-CON
470␮F 10V ’E’ low ESR
150␮F 6V PTH low ESR
120␮f 6V SMT low ESR
C OUT
680␮F x 2
6CV680GX
680␮F 6V SMT Bulk Capacitor
OR
OR
Sanyo
C1
1␮F
Generic
1 F,10V.X7R Dielectric
C2
1␮F
Generic
1 F,4V.X7R Dielectric
C3
330pF
Generic
330pF,4V.X7R Dielectric
C4
1␮F
Generic
1 F,10V.X7R Dielectric
C5
1␮F
Generic
1 F,10V.X7R Dielectric
C6
1␮F
Generic
1 F,4V.X7R Dielectric
C7
22␮F
Generic
22 F,4V.X7R Dielectric
C8
2.2␮F
Generic
2.2 F,10V.X7R Dielectric
C9
1␮F
Generic
1 F,10V.X7R Dielectric
C10
1␮F
Generic
1 F,10V.X7R Dielectric
C11
1␮F
Generic
1 F,10V.X7R Dielectric
*Cx1
0.022␮F
Generic
0.022 F,4V.X7R Dielectric
*Cx2
10nF
Generic
10nF,10V.X7R Dielectric
L1
15␮H
CDRH127B-OWZ9
Sumida SMT
Low Profile SMT
2785044447
FairRite
SMT Ferrite Bead
Fx
* see Optimising for Transient Response Section
ISSUE 3 - MAY 2000
13
ZXRD1000 SERIES
4.5V -10VInput, 3.3V/4A Output, N Phase, High Efficiency Non-Synchronous Step
Down Converter 200kHz
VCC
4.5-10.0V
IC1
R1
13
9 SHDN
Shut Down
CIN
11 LBF
RSENSE+ 7
14
10
6
5
RSENSE -
Delay
Decoup
VINT
CT
4
C2
C3
C4
L1
C11
C9
R2
D1
3
C7
VOUT
3.3V 4A
RSENSE
C6
8
VF B 16
Comp
15
PWR
GND
N1
C10
2
Bootstrap 1
GND
C1
VDRIVE
LBSET
C5
Low input flag
C8
D2
VIN
COUT
R4
D3
R3
100
95
VIN=5V
Efficiency (%)
90
VIN=10V
85
80
75
70
65
60
Efficiency v IOUT
VOUT=3.3V.
55
50
0.1
1
ZXRD1033NQ16
10
IOUT (A)
100
VIN=7V
Efficiency (%)
95
90
VIN=10V
85
80
75
70
65
Efficiency v IOUT
VOUT=5V.
60
55
50
0.1
1
IOUT (A)
14
ZXRD1050NQ16
10
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Ref
Part Number
Manufacturer
Comments
IC1
Value
ZXRD1033NQ16
Zetex
QSOP16 Controller IC
N1
V IN >7V
V IN <7V
Zetex
ZXM64N03X
ZXM64N02X
MSOP8 Low RDS(ON)
N MOSFET
30V V DS
20V V DS
D1
5A 0.5V V F
50WQ04FN
Zetex
Schottky Diode 5A
D2
10mA 0.4V V F
BAT54
Zetex
SOT23 Schottky Diode
D3
10mA 0.4V V F
BAT54
Zetex
SOT23 Schottky Diode
R1
100k
WCR0805-100k
Welwyn/IRC
0805 Size
R2
680⍀
WCR0805-680
Welwyn/IRC
0805 Size
0805 Size
R3
24k
WCR0805-24k
Welwyn/IRC
*R3
3k
WCR0805-3k
Welwyn/IRC
0805 Size
R4
10k
WCR0805-10k
Welwyn/IRC
0805 Size
*Rx
2.7K
WCR0805-2.7k
Welwyn/IRC
0805 Size
R SENSE
0.01⍀
LR1206R010
Welwyn/IRC
Current Limit Sense Resistor
C IN
68␮F
68␮F
68␮F
TPSC68M02R0150
20SA68M
20SV68M
AVX
Sanyo OS-CON
Sanyo OS-CON
68␮F 25V ’E’ low ESR
68␮F 20V PTH low ESR
68␮F 20V SMT low ESR
C OUT
OR
OR
470␮F
*150␮F
*120␮F
TPSE477M010R0200 AVX
6SA150M
Sanyo OS-CON
6SV120M
Sanyo OS-CON
470␮F 10V ’E’ low ESR
150␮F 6V PTH low ESR
120␮f 6V SMT low ESR
C OUT
680␮F x 2
6CV680GX
680␮F 6V SMT Bulk Capacitor
C1
1␮F
Generic
1 F,10V.X7R Dielectric
C2
1␮F
Generic
1 F,4V.X7R Dielectric
C3
330pF
Generic
330pF,4V.X7R Dielectric
C4
1␮F
Generic
1 F,10V.X7R Dielectric
C5
1␮F
Generic
1 F,10V.X7R Dielectric
C6
1␮F
Generic
1 F,4V.X7R Dielectric
C7
22␮F
Generic
22 F,4V.X7R Dielectric
C8
2.2␮F
Generic
2.2 F,10V.X7R Dielectric
C9
1␮F
Generic
1 F,10V.X7R Dielectric
C10
1␮F
Generic
1 F,10V.X7R Dielectric
C11
1␮F
Generic
1 F,10V.X7R Dielectric
OR
OR
Sanyo
*Cx1
0.022␮F
Generic
0.022 F,4V.X7R Dielectric
*Cx2
10nF
Generic
10nF,10V.X7R Dielectric
L1
OR
15␮H
15␮H
Sumida
Coilcraft
Low Profile SMT
Low Profile SMT
CDRH127-150MC
DP5022P-153
* see Optimising for Transient Response Section
ISSUE 3 - MAY 2000
15
ZXRD1000 SERIES
5V -18V Input, 5V/3A Output, P Phase, High Efficiency SimpleSyncTM Converter 200kHz
VCC
5V-18V
IC1
R1
13
VIN
9
Shut Down
VDRIVE
SHDN
P1
2
L1
C5
11
Low input flag
LBF
RSENSE+
14
10 Delay
6 Decoup
5 VINT
CT
CIN
GND
4
C1
C2
C3
C4
RSENSE -
VOUT
5.0V 3A
RSENSE
Bootstrap 1
LBSET
7
16
VF B
Comp 15
PWR
GND
D1
C6
8
Fx
N1
R2
C9
C8
3
COUT
C7
R3
100
95
VIN=5V
Efficiency (%)
90
VIN=12V
85
80
75
70
65
60
Efficiency v IOUT
VOUT=3.3V.
55
50
0.1
100
10
1
IOUT (A)
VIN=7V
95
Efficiency (%)
ZXRD1033PQ16
90
VIN=12V
85
80
75
70
65
Efficiency v IOUT
VOUT=5V.
60
55
50
0.1
1
IOUT (A)
16
ZXRD1050PQ16
10
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Ref
Value
IC1
P1
V IN >12V
V IN <12V
Part Number
Manufacturer
Comments
ZXRD1050PQ16
Zetex
QSOP16 Controller IC
Zetex
MSOP8 Low RDS(ON)
P MOSFET
30V VDS
20V V DS
ZXM64NO3X
Zetex
MSOP8 Low RDS(ON) MOSFET
ZHCS1000
Zetex
Schottky Diode 1A
ZXM64P03X
ZXM64P02X
N1
D1
1A 0.5V V F
R1
100k
WCR0805-100k
Welwyn/IRC
0805 Size
R2
680⍀
WCR0805-680
Welwyn/IRC
0805 Size
R3
24k
WCR0805-24k
Welwyn/IRC
0805 Size
*R3
3k
WCR0805-3k
Welwyn/IRC
0805 Size
*Rx
2.7K
WCR0805-2.7k
Welwyn/IRC
0805 Size
R SENSE
0.015⍀
LR1206R015
Welwyn/IRC
Current Limit Sense Resistor
C IN
68␮F
68␮F
68␮F
TPSV686M025R0150 AVX
20SA68M
Sanyo OS-CON
20SV68M
Sanyo OS-CON
68␮F 25V ’E’ low ESR
68␮F 20V PTH low ESR
68␮F 20V SMT low ESR
C OUT
OR
OR
470␮F
*150␮F
*120␮F
TPSE477M010R0200 AVX
6SA150M
Sanyo OS-CON
6SV120M
Sanyo OS-CON
470␮F 10V ’E’ low ESR
150␮F 6V PTH low ESR
120␮f 6V SMT low ESR
C OUT
680␮F x 2
6CV680GX
680␮F 6V SMT Bulk Capacitor
C1
1␮F
Generic
1 F,20V.X7R Dielectric
C2
1␮F
Generic
1 F,4V.X7R Dielectric
C3
330pF
Generic
330pF,4V.X7R Dielectric
C4
1␮F
Generic
1 F,20V.X7R Dielectric
C5
1␮F
Generic
1 F,20V.X7R Dielectric
C6
1␮F
Generic
1 F,4V.X7R Dielectric
C7
22␮F
Generic
22 F,4V.X7R Dielectric
C8
2.2␮F
Generic
2.2 F,20V.X7R Dielectric
C9
1␮F
Generic
1 F,20V.X7R Dielectric
*Cx1
0.022␮F
Generic
0.022 F,4V.X7R Dielectric
Generic
10nF,20V.X7R Dielectric
OR
OR
*Cx2
10nF
L1
15␮H
Fx
Sanyo
CDRH127B-OWZ9
Sumida
Low Profile SMT
2785044447
FairRite
SMT Ferrite Bead
* see Optimising for Transient Response Section
ISSUE 3 - MAY 2000
17
ZXRD1000 SERIES
5V -18V Input, 5V/3A Output, P Phase, High Efficiency Non-synchronous Step Down
Converter 200kHz
VCC
5.0-18V
IC1
R1
C8
13
VIN
9
Shut Down
VDRIVE
SHDN
P1
2
L1
LBSET
C5
Low input flag
Bootstrap
11 LBF
RSENSE+
14
10
6
5
RSENSE -
CIN
Delay
Decoup
VINT
CT
GND
4
C1
C2
C3
C4
VOUT
5.0V 3A
RSENSE
1
7
C6
8
16
VF B
Comp
15
PWR
GND
C9
R2
D1
3
COUT
C7
R3
100
95
VIN=5V
Efficiency (%)
90
VIN=12V
85
80
75
70
65
60
Efficiency v IOUT
VOUT=3.3V.
55
50
0.1
1
ZXRD1033PQ16
10
IOUT (A)
100
Efficiency (%)
95
VIN=7V
90
VIN=12V
85
80
75
70
65
Efficiency v IOUT
VOUT=5V.
60
55
50
0.1
1
IOUT (A)
18
ZXRD1050PQ16
10
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Ref
Value
IC1
P1
V IN >12V
V IN <12V
Part Number
Manufacturer
Comments
ZXRD1050PQ16
Zetex
QSOP16 Controller IC
Zetex
MSOP8 Low RDS(ON)
P MOSFET
30V VDS
20V V DS
ZXM64P03X
ZXM64P02X
D1
5A 0.5V V F
50WQ04FN
IR
Schottky Diode 5A
R1
100k
WCR0805-100k
Welwyn/IRC
0805 Size
R2
680⍀
WCR0805-680
Welwyn/IRC
0805 Size
R3
24k
WCR0805-24k
Welwyn/IRC
0805 Size
*R3
3k
WCR0805-3k
Welwyn/IRC
0805 Size
*Rx
2.7k
WCR0805-2.7k
Welwyn/IRC
0805 Size
R SENSE
0.015⍀
LR1206R015
Welwyn/IRC
Current Limit Sense Resistor
C IN
68␮F
68␮F
68␮F
TPSV686M025R0150 AVX
20SA68M
Sanyo OS-CON
20SV68M
Sanyo OS-CON
68␮F 25V ’E’ low ESR
68␮F 20V PTH low ESR
68␮F 20V SMT low ESR
C OUT
OR
OR
470␮F
*150␮F
*120␮F
TPSE477M010R0200 AVX
6SA150M
Sanyo OS-CON
6SV120M
Sanyo OS-CON
470␮F 10V ’E’ low ESR
150␮F 6V PTH low ESR
120␮f 6V SMT low ESR
C OUT
680␮F x 2
6CV680GX
680␮F 6V SMT Bulk Capacitor
OR
OR
Sanyo
C1
1␮F
Generic
1 F,20V.X7R Dielectric
C2
1␮F
Generic
1 F,4V.X7R Dielectric
C3
330pF
Generic
330pF,4V.X7R Dielectric
C4
1␮F
Generic
1 F,20V.X7R Dielectric
C5
1␮F
Generic
1 F,20V.X7R Dielectric
C6
1␮F
Generic
1 F,4V.X7R Dielectric
C7
22␮F
Generic
22 F,4V.X7R Dielectric
C8
2.2␮F
Generic
2.2 F,20V.X7R Dielectric
C9
1␮F
Generic
1 F,20V.X7R Dielectric
*Cx1
0.022␮F
Generic
0.022 F,4V.X7R Dielectric
*Cx2
10nF
Generic
10nF,20V.X7R Dielectric
L1
15␮H
15␮H
Sumida SMT
Coilcraft
Low Profile SMT
Low Profile SMT
CDRH127-150MC
D05022P-153
* see Optimising for Transient Response Section
ISSUE 3 - MAY 2000
19
ZXRD1000 SERIES
Designing with the ZXRD and Dynamic
Performance
Startup
This section refers to the reference design for the 3.3V,
4A output N channel synchronous converter. This is
as shown previously in the Optimising for transient
response section of the applications information (page
10). This circuit is also representative of the ZXRD
evaluation board (see ordering information).
Startup is always important in DC-DC converter
applications. Magnetics have large inrush current
requirements. For higher current applications using
large input and output capacitors the startup current can
be quite significant. This can cause several problems.
In many applications the power supply to the DC-DC
converter can be affected. Particularly in battery
powered applications, trying to take large steps in
load current out of the supply can result in either
current limitation (by the internal impedance of the
battery), or it can actually damage the battery.
The ZXRD series has been designed to give the best
in terms of all round flexibility allowing engineers to
either use the reference design as is, or to tailor the
design to the individual requirements. This section
demonstrates the performance features of the ZXRD
series and its associated components.
For the converter itself, large changes in load current
can result in false triggering of the RSENSE circuit. This
could result in device hiccup (see applications section).
Efficiency
Efficiency is often quoted as one of the key parameters
of a DC-DC converter. Not only does it give an
instantaneous idea of heat dissipation, but also an idea
as to the extent battery life can be extended in say
portable applications. Fig.1 shows the efficiency of the
standard application circuit. Efficiency vs Output
current is shown for the 5 to 3.3V configuration.
The ZXRD programmable soft start function
eliminates both these problems. This is very clear to
see in operation if the main switching waveforms are
examined.
The soft start is programmed by the combination of
resistor and capacitor R3 and C7. As a recommendation,
R3 and C7 are set to 3k and 22F respectively, which limits
the peak startup current appropriately in the reference
circuit. Fig.2 shows the startup waveforms. VIN and VOUT
are plotted against time
100
VIN=5V
Efficiency (%)
95
90
85
80
75
70
65
Efficiency v IOUT
VOUT=3.3V.
60
55
50
0.1
1
IOUT (A)
10
Fig.1. 5-3.3V Efficiency to 4A
20
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Output Voltage Ripple
Output voltage ripple is shown in Fig.4 and Fig. 5
for load currents of 0.5A and 4A respectively.
Output voltage ripple will be dependant, to a very
large extent, on the output capacitor ESR. (see
Applications Section for ripple calculation).
Fig.2. Startup Waveform for 3.3V output .
SimpleSyncTM and Shoot-Through
Steady state operation under constant load gives
an excellent indication of the ZXRD series
performance and also demonstrates how well
SimpleSyncTM w o r k s. T he Si mp le Sy n cTM
technique drives the synchronous MOSFET gate
using the overwinding on the main inductor. It
also uses the high speed suppression characteristics
of the ferrite bead to prevent shoot through
currents. Fig.3 shows the gate waveforms for the
main and synchronous MOSFET devices (Zetex
ZXM64N02X).
Fig.4 0.5A Main & VOUT Waveforms
Fig.5 4A Main & VOUT Waveforms
Fig3. Main & Synchronous gate waveforms
ISSUE 3 - MAY 2000
21
ZXRD1000 SERIES
Line regulation
Transient Response
Variation in input voltage for both these conditions
(0.5A and 4A output) shows the excellent line
regulation the ZXRD. Fig.6 shows that with 0.5A and
4A output currents, applying an increase in input
voltage from 5V to 10V , results in only small changes
in output regulation.
Transient response to changes in load is becoming an
increasingly critical feature of many converter circuits.
Many high speed processors make very large step
changes in their load requirements, at the same time
as having more stringent specifications in terms of
overshoot and undershoot. Fig.7 demonstrates the
excellent load transient performance of the ZXRD
series. A step change using an electronic load from 1A
to 3A is shown with corresponding output transient
performance.
Fig.6a Line Regulation 0.5A load
Fig.6b Line Regulation 4A load
Fig.7 Output Transient Response
Non-synchronous Applications
One of the key features of the ZXRD series, when
combined with the SimpleSyncTM technique, is the
flexibility in allowing engineers to choose either a
synchronous or non-synchronous architecture.
Making the design non-synchronous by removing
MOSFET N2 (the synchronous device), replacing the
ZHCS1000 with a high current diode (50WQ04FN)
and using a 2 terminal inductor, such as the Sumida
CDRH127-150MC, decreases cost slightly at the
expense of a few efficiency points. Fig.8 shows the
effect on the efficiency of the 5 to 3.3V 4A application
when the design is made non-synchronous.
22
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
100
95
VIN=5V
Efficiency (%)
90
85
80
75
70
65
60
Efficiency v IOUT
VOUT=3.3V.
55
50
0.1
1
10
IOUT (A)
Fig.8 Efficiency for non-synchronous 5-3.3V conversion
Using ’P’ Channel Devices (No Bootstrap)
If the same package size MOSFET devices are used, it
is likely a higher on resistance will be encountered,
with the result that efficiency will decline slightly.
Fig 9 shows the efficiency plot for a P phase
s y n c h r o n o u s 5 V co n v e r t e r b a s e d o n t he
ZXRD1050PQ16. The figure charts efficiency v output
current at 12V input and 7V input.
All the preceeding examples utilise N channel
MOSFET devices and a bootstrap circuit to provide full
enhancement to the high side device. These circuits
ha ve a ma ximum input voltage of 10V. For
applications requiring a higher input voltage, using P
channel devices for the main MOSFET will allow up to
18V operation. Typically this may be in a 12V to 5V
converter circuit.
100
VIN=7V
Efficiency (%)
95
90
VIN=12V
85
80
75
70
65
Efficiency v IOUT
VOUT=5V.
60
55
50
0.1
1
IOUT (A)
Fig.9 ’P’ Channel Device Efficiency (synchronous)
ISSUE 3 - MAY 2000
23
10
ZXRD1000 SERIES
ZXCM6 Series
Low voltage MOSFETs
Unique structure gives optimum performance for switching applications.
N channel devices offer high efficiency
performance for switching applications.
P channel MOSFETs excel in load
switching applications.
This family of MOSFETs from Zetex offers a
combination of low on-resistance and low gate charge,
providing optimum performance and high efficiency
for switching applications such as DC - DC conversion.
The P-channel MOSFETs offer highly efficient
pe rforma nce for low v olta ge loa d switching
applications. This helps increase battery life in portable
equipment.
On resistance is low across the family, from only 40m
(max) for the ZXM64N02X part up to 180m (max) for
the ZXM61N02F. This means that on-state losses are
minimised, improving efficiency in low frequency drive
applications. Threshold voltages of 0.7V and 1V
minimum allow the MOSFETs to be driven from low
voltage sources.
Minimum threshold voltage is low, only 0.7V or 1V,
e n a b l i n g t h e M O SF E Ts to pr ov i de o pti mu m
performance from a low voltage source. To ensure the
device suitability for low voltage applications, drain to
source voltage is specified at 20V or 30V.
To minimise on-state losses, and improve efficiency in
in low frequency drive applications, the on-resistance
To minimise switching losses, and hence increase the (RDS(ON)) is low across the range. For example, the
efficiency of high frequency operation, gate charge (Qg) ZXM64P03X has an RDS(ON) of only 100m at a gate to
is small. The maximum Qg varies from 3.4nC to 16nC source voltage of 4.5V.
depending on which device is chosen. Crss (Miller Gate source charge is also low, easing requirements for
capacitance) is also low, e.g. typically 30pF for the the gate driver. Maximum values range from 0.62nC for
ZXM6203E6 device. This results in better efficiency in the ZXM61P03F, up to 9nC for the ZXM64P03X.
high frequency applications.
Small outline surface mount packaging
The products have been designed to optimise the
performance of a range of packages. The parts are
offered in SOT23, SOT23-6 and MSOP8 packages. The
MSOP8 enables single or dual devices to be offered.
The MSOP8 is also half the size of competitive SO8
devices and 20% smaller than TSSOP8 alternatives.
Product performance
The following performance characteristics show the
capabilities of the ZXM64N02X. This device is
recommended for use with certain configurations of
the ZXRD DCDC controller circuit.
24
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Performance Characterisation of ZXM64N02X
ELECTRICAL CHARACTERISTICS (at Tamb = 25°C unless otherwise stated).
PARAMETER
SYMBOL MIN.
TYP.
MAX.
UNIT CONDITIONS.
STATIC
Drain-Source Breakdown Voltage
V (BR)DSS 20
Zero Gate Voltage Drain Current
I DSS
Gate-Body Leakage
I GSS
Gate-Source Threshold Voltage
V GS(th)
Static Drain-Source On-State
Resistance (1)
R DS(on)
Forward Transconductance (3)
g fs
V
I D =250 A, V GS =0V
1
A
V DS =20V, V GS =0V
100
nA
V GS = 12V,
V DS =0V
V
I D =250 A, V DS =
V GS
V GS =4.5V, I D =3.8A
V GS =2.7V, I D =1.9A
S
V DS =10V,I D =1.9A
0.7
0.040
0.050
6.1
DYNAMIC (3)
Input Capacitance
C iss
1100
pF
Output Capacitance
C oss
350
pF
Reverse Transfer Capacitance
C rss
100
pF
Turn-On Delay Time
t d(on)
5.7
ns
Rise Time
tr
9.6
ns
Turn-Off Delay Time
t d(off)
28.3
ns
Fall Time
tf
11.6
ns
Total Gate Charge
Qg
16
nC
Gate-Source Charge
Q gs
3.5
nC
Gate Drain Charge
Q gd
5.4
nC
Diode Forward Voltage (1)
V SD
0.95
V
T j =25°C, I S =3.8A,
V GS =0V
Reverse Recovery Time (3)
t rr
23.7
ns
Reverse Recovery Charge(3)
Q rr
13.3
nC
T j =25°C, I F =3.8A,
di/dt= 100A/ s
V DS =15 V,
V GS =0V, f=1MHz
SWITCHING(2) (3)
V DD =10V, I D =3.8A
R G =6.2 , R D =2.6 (Refer to test
circuit)
V DS =16V,V GS =4.5V
, I D =3.8A
(Refer to test
circuit)
SOURCE-DRAIN DIODE
(1) Measured under pulsed conditions. Width=300s. Duty cycle 2% .
(2) Switching characteristics are independent of operating junction temperature.
(3) For design aid only, not subject to production testing.
ISSUE 3 - MAY 2000
25
ZXRD1000 SERIES
Zetex
GERMANY
Zetex GmbH
Munich
ASIA
Zetex Asia
Hong Kong
USA
Zetex Inc
Long Island NY
UK
Zetex PLC
Chadderton,
Oldham
(49) 894549490
(852) 2610 0611
(1) 631 543 7100
(44) 161 622 4444
Sumida Electric
HK
(852) 2880 6688
Sumida Electric
USA (CHICAGO
Head Office)
Ole Wolf
Electronics Ltd.
Taiwan Sumida
Electric
(886) 2762 2177
(1) 847 956-0666
(44) 1525 290755
Fair Rite Asia Pte
Ltd Singapore
(65) 281 1969
Japan/Korea
(81) 332255055
FairRite Products
Corp
(1) 914 895 2055
Schaffner EMC Ltd
(44) 118 977 0070
AVX Asia
Singapore
(65) 258 2833
AVX USA
(1) 843 448 9411
AVX UK
(44) 1252 770000
IRC Inc
(1) 512 992 7900
Welwyn
Components Ltd
(44) 1670 822181
Coilcraft Inc
(1) 847 639 6400
Coilcraft Europe
(44) 1236 730595
SANYO
Electronics Ltd.
Forrest City, AR
870 633 5030
San Diego, CA
619 661 6835
Rochelle Pk, NJ
201 843 8100
Semicon UK Ltd
(44) 1279 422224
http://www.zetex.com
Sumida
http://www.japanlink.com/sumida/
FairRite
Schaffner
Electronik GmbH
(49) 72156910
AVX
http://www.avxcorp.com
Welwyn, IRC
Welwyn
Electronics GmbH
(49)871 973760
TTC Group plc
Singapore
(65) 536 51667
http://welwyn-tt.co.uk
Coilcraft
http://www.coilcraft.com
Sa ny o Ele ctronic Sanyo Europe
Munich
Comp. (OS-CON)
(49) 89 457693 16
SANYO
Electronics Ltd.
Hong Kong
(852) 21936888
Singapore
(65) 281 3226
Japan
(81) 720 70 6306
http://www.sanyovideo.com
26
ISSUE 3 - MAY 2000
ZXRD1000 SERIES
Connection Diagram
Bootstrap
1
16
VFB
Note:
VDRIVE
2
15
Comp
PWRGND
3
14
Delay
Connection diagram is the same for N and P Phase, adjustable and
fixed controllers. The VFB pin has a different function between
adjustable and fixed versions.
GND
4
13
VIN
CT
5
12
VINT
6
11
LBSET
LBF
RSENSE +
7
10
Decoup
RSENSE -
8
9
SHDN
Package Dimensions
A
IDENTIFICATION
RECESS
FOR PIN 1
C
E
J
B
D
F
PIN No.1
G
K
DIM
Millimetres
Inches
MIN
MAX
MIN
MAX
A
4.80
4.98
0.189
0.196
B
0.635
C
0.177
0.267
0.007
0.011
D
0.20
0.30
0.008
0.012
E
3.81
3.99
0.15
0.157
F
1.35
1.75
0.053
0.069
G
0.10
0.25
0.004
0.01
0.025 NOM
J
5.79
6.20
0.228
0.244
K
0°
8°
0°
8°
ISSUE 3 - MAY 2000
27
ZXRD1000 SERIES
Ordering Information
Device
Description
T&R Suffix
Partmarking
ZXRD1033NQ16
3.3V Fixed controller N main switch
TA, TC
ZXRD1033N
ZXRD1050NQ16
5.0V Fixed controller N main switch
TA, TC
ZXRD1050N
ZXRD100ANQ16
Adjustable controller N main switch
TA, TC
ZXRD100AN
ZXRD1033PQ16
3.3V Fixed controller P main switch
TA, TC
ZXRD1033P
ZXRD1050PQ16
5.0V Fixed controller P main switch
TA, TC
ZXRD1050P
ZXRD100APQ16
Adjustable controller P main switch
TA, TC
ZXRD100AP
’N main switch’ indicates controller for use with N channel main switch element.
’P main switch’ indicates controller for use with P channel main switch element.
TA= Tape and Reel quantity of 500
TC= Tape and Reel quantity of 2500
Demonstration Boards
These can be requested through your local Zetex office or representative. These boards can be tailored to your
specific needs. If you would like to obtain a demo board then a request form is available to help determine your
exact requirement.
Zetex plc.
F ields New R oad, C hadderton, Oldham, OL9-8NP, United Kingdom.
T elephone: (44)161 622 4422 (S ales), (44)161 622 4444 (General E nquiries)
F ax: (44)161 622 4420
Zetex GmbH
S treitfeldstraße 19
D-81673 München
Germany
T elefon: (49) 89 45 49 49 0
F ax: (49) 89 45 49 49 49
Zetex Inc.
47 Mall Drive, Unit 4
C ommack NY 11725
US A
T elephone: (631) 543-7100
F ax: (631) 864-7630
Zetex (Asia) Ltd.
3510 Metroplaza, T ower 2
Hing F ong R oad,
Kwai F ong, Hong Kong
T elephone:(852) 26100 611
F ax: (852) 24250 494
T hese are supported by
agents and distributors in
major countries world-wide
Zetex plc 2000
Internet:http://www.zetex.com
T his publication is issued to provide outline information only which (unless agreed by the C ompany in writing) may not be used, applied or reproduced for any
purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. T he C ompany reserves the
right to alter without notice the specification, design, price or conditions of supply of any product or service.
28
ISSUE 3 - MAY 2000