TDA21321 Data Sheet (1.2 MB, EN)

High -P erf or manc e Dr BL AD E
6.6 mm x 4.5 mm x 0.6 mm
TD A21 321
Dat a She et
Revision 2.4, 2015-07-16
Po wer Ma nage m ent and M ulti M ark e t
Edition 2015-07-1626
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2015 Infineon Technologies AG
All Rights Reserved.
Legal Disclaimer
The information given in this document shall in no event be regarded as a guarantee of conditions or
characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any
information regarding the application of the device, Infineon Technologies hereby disclaims any and all
warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual
property rights of any third party.
Information
For further information on technology, delivery terms and conditions and prices, please contact the nearest
Infineon Technologies Office (www.infineon.com).
Warnings
Due to technical requirements, components may contain dangerous substances. For information on the types in
question, please contact the nearest Infineon Technologies Office.
Infineon Technologies components may be used in life-support devices or systems only with the express written
approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the
failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life
support devices or systems are intended to be implanted in the human body or to support and/or maintain and
sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other
persons may be endangered.
TDA21321
Revision History
Page or Item
Subjects (major changes since previous revision)
Revision 2.4, 2015-07-16
Package drawings figures 18 – 20 updated
Inserted chapter 10 (packaging information)
Trademarks of Infineon Technologies AG
AURIX™, BlueMoon™, C166™, CanPAK™, CIPOS™, CIPURSE™, COMNEON™, EconoPACK™,
CoolMOS™, CoolSET™, CORECONTROL™, CROSSAVE™, DAVE™, EasyPIM™, EconoBRIDGE™,
EconoDUAL™, EconoPIM™, EiceDRIVER™, eupec™, FCOS™, HITFET™, HybridPACK™, I²RF™,
ISOFACE™, IsoPACK™, MIPAQ™, ModSTACK™, my-d™, NovalithIC™, OmniTune™, OptiMOS™, ORIGA™,
PRIMARION™, PrimePACK™, PrimeSTACK™, PRO-SIL™, PROFET™, RASIC™, ReverSave™, SatRIC™,
SIEGET™, SINDRION™, SIPMOS™, SMARTi™, SmartLEWIS™, SOLID FLASH™, TEMPFET™, thinQ!™,
TRENCHSTOP™, TriCore™, X-GOLD™, X-PMU™, XMM™, XPOSYS™.
Other Trademarks
Advance Design System™ (ADS) of Agilent Technologies, AMBA™, ARM™, MULTI-ICE™, KEIL™,
PRIMECELL™, REALVIEW™, THUMB™, µVision™ of ARM Limited, UK. AUTOSAR™ is licensed by
AUTOSAR development partnership. Bluetooth™ of Bluetooth SIG Inc. CAT-iq™ of DECT Forum.
COLOSSUS™, FirstGPS™ of Trimble Navigation Ltd. EMV™ of EMVCo, LLC (Visa Holdings Inc.). EPCOS™
of Epcos AG. FLEXGO™ of Microsoft Corporation. FlexRay™ is licensed by FlexRay Consortium.
HYPERTERMINAL™ of Hilgraeve Incorporated. IEC™ of Commission Electrotechnique Internationale. IrDA™
of Infrared Data Association Corporation. ISO™ of INTERNATIONAL ORGANIZATION FOR
STANDARDIZATION. MATLAB™ of MathWorks, Inc. MAXIM™ of Maxim Integrated Products, Inc.
MICROTEC™, NUCLEUS™ of Mentor Graphics Corporation. Mifare™ of NXP. MIPI™ of MIPI Alliance, Inc.
MIPS™ of MIPS Technologies, Inc., USA. muRata™ of MURATA MANUFACTURING CO., MICROWAVE
OFFICE™ (MWO) of Applied Wave Research Inc., OmniVision™ of OmniVision Technologies, Inc.
Openwave™ Openwave Systems Inc. RED HAT™ Red Hat, Inc. RFMD™ RF Micro Devices, Inc. SIRIUS™ of
Sirius Satellite Radio Inc. SOLARIS™ of Sun Microsystems, Inc. SPANSION™ of Spansion LLC Ltd.
Symbian™ of Symbian Software Limited. TAIYO YUDEN™ of Taiyo Yuden Co. TEAKLITE™ of CEVA, Inc.
TEKTRONIX™ of Tektronix Inc. TOKO™ of TOKO KABUSHIKI KAISHA TA. UNIX™ of X/Open Company
Limited. VERILOG™, PALLADIUM™ of Cadence Design Systems, Inc. VLYNQ™ of Texas Instruments
Incorporated. VXWORKS™, WIND RIVER™ of WIND RIVER SYSTEMS, INC. ZETEX™ of Diodes Zetex
Limited.
Last Trademarks Update 2010-10-26
Data Sheet
3
Revision 2.4, 2015-07-16
TDA21321
Applications
Applications
1




Desktop and Server Vcore and non-Vcore buck-converter
Single Phase and Multiphase POL
CPU/GPU Regulation in Notebook, Desktop Graphics Cards, DDR Memory, Graphic Memory
High Power Density Voltage Regulator Modules (VRM).
Features
2














Input voltage range +4.5 V to +16 V
Maximum average current up to 50 A
For synchronous Buck step down voltage applications
Power MOSFETs rated 25 V for safe operation under all conditions
Fast switching technology for improved performance at high switching frequencies (> 750 kHz)
Includes bootstrap diode
Shoot through protection
Max +8 V VGS, high-side and low-side MOSFET gate driving voltage
Compatible to standard +3.3 V PWM controller integrated circuits
Tri-state PWM input functionality
Small package: LG-WIQFN-38-1 (6.6x4.5x0.6 mm³)
RoHS compliant
Integrated temperature sense
Integrated current sense
Table 1
Product Identification
Part Number
Temp Range
Package
Marking
TDA21321
-25C to 125C
LG-WIQFN-38-1 (6.6x4.5x0.6 mm³)
TDA21321
Figure 1
Data Sheet
Picture of the Product
4
Revision 2.4, 2015-07-16
TDA21321
Description
3
Description
3.1
Pinout
Figure 2
Pinout, Numbering and Name of Pins (transparent top view)
Table 2
I/O Signals
Pin No.
Name
Pin Type Buffer Type Function
2
PWM
I/O
+3.3 V logic
3
OFF#
I
+3.3 V logic
4
IMON
O
Analog
5
IMONREF
O
Analog
7
TMON/FAULT O
Analog/
Digital
8
BOOT
I
Analog
9
PHASE
I
Analog
33-38
(pads)
SW
O
Analog
Data Sheet
PWM drive logic input, Status output for VCIN
The tri-state PWM input is compatible with 3.3 V.
Deactivates LS-MOSFET
Pull low to prevent LS-FET turn-on. Leave open if not used.
(If traced out in noisy layout it may require external pull up.)
Load current Sensing
Provides a voltage proportional to the high/low-side
MOSFET currents; Leave open if not used.
Load current Sensing
Reference to pin 4; Leave open if not used.
Thermal Sensing / Fault Pin
Temperature reporting, fault signaling by logic “H”; Status
output of VDRV, Leave open if not used.
Bootstrap voltage pin
Connect to BOOT capacitor
Switch node input
Internally connected to SW pins, Connect to BOOT
capacitor as reference pin for boot voltage
Switch node output
High current output switching node
5
Revision 2.4, 2015-07-16
TDA21321
Description
Table 3
Pin No.
Power Supply
Pin Type
Function
13 – 15, 20, VIN
23-28 (pads)
POWER
21
VDRV
POWER
22
VCIN
POWER
Input voltage
Converter input voltage (connected to drain of the high-side MOSFET and
driver)
MOSFET gate drive supply voltage
High and low-side gate drive
Driver logic supply voltage
bias voltage for the internal logic
Table 4
Name
Ground Pins
Pin No.
Name
Pin Type
Function
1
CGND
GND
16 – 19,
PGND
29-32 (pads)
GND
Control signal ground
Should be connected to local PGND externally, preferably by vias to GND
plane
Power ground
All these pins must be connected to the power GND plane through multiple
low inductance vias.
Table 5
Pin No.
Not Connected
Name
6, 10, 11, 12 NC
Data Sheet
Pin Type
Function
–
No internal connection
Leave pin floating, tie to VIN or GND.
6
Revision 2.4, 2015-07-16
TDA21321
Description
3.2
General Description
The Infineon TDA21321 is a multichip module that incorporates Infineon’s premier MOSFET technology into a
single high-side and a single low-side MOSFET. This is coupled with a robust, high performance, high switching
frequency gate driver on a single 38 pin LG-WIQFN-38-1 (6.6x4.5x0.6 mm³) package. The optimized gate timing
enables significant light load efficiency improvements over discrete solutions. State of the art MOSFET
technology provides exceptional performance at full and light load.
When combined with Infineon’s Primarion™ Controller Family of Digital Multi-phase Controllers, the TDA21321
forms a complete core-voltage regulator solution for advanced micro and graphics processors as well as pointof-load applications. The device package height is 0.6 mm. It is an excellent choice for applications with critical
height limitations and has reduced thermal impedance from junction to top case compared to DrMOS, allowing
for top side cooling.
2
The power density for transmitted power of this approach is approximately 50 W within a 28 mm area.
Figure 3
Simplified Block Diagram
Attention: GH and GL are not accessible on this package, but are mentioned for clarity in this block
diagram.
Data Sheet
7
Revision 2.4, 2015-07-16
TDA21321
Electrical Specification
4
Electrical Specification
4.1
Absolute Maximum Ratings
Note: TA = 25°C
Stresses above those listed in Table 6 “Absolute Maximum Ratings” and Figure 4 “Repetitive Voltage Stress at
Phase Node - Safe Operating Area” may cause permanent damage to the device. These are absolute stress
ratings only and operation of the device is not implied or recommended at these or any other conditions in
excess of those given in the operational sections of this specification. Exposure over values of the
recommended ratings (Table 8) for extended periods may adversely affect the operation and reliability of the
device.
Table 6
Absolute Maximum Ratings
Parameter
Symbol
Frequency of the PWM input
fSW
Maximum average load current
Values
Unit
Note / Test Condition
Min.
Typ.
Max.
–
1.2
MHz
rated current sense
accuracy between
100 kHz and 800 kHz
IOUT
0.01
(in
CCM)
–
–
50
A
–
Input Voltage
VIN (DC)
-0.30
–
18
V
–
Logic supply voltage
VCIN (DC)
-0.30
–
9
V
–
High and low-side driver voltage
VDRV (DC)
-0.30
–
9
V
–
Switch node voltage
VSW (DC)
-1
–
18
V
–
PHASE voltage pin (9)
BOOT voltage
1
1
VSW (AC)
-10
–
25
V
–
VPHASE (DC)
-1
–
18
V
–
VPHASE (AC)
1
-10
–
25
V
–
VBOOT (DC)
-0.3
–
25
V
–
1
–
30
V
–
VBOOT-PHASE (DC) -0.3
–
9
V
–
VBOOT (AC)
–
1
OFF# voltage
VOFF#
-0.3
–
4
V
PWM voltage
VPWM
-0.3
–
4
V
TMON/FAULT
VTMON/FAULT
-0.3
–
3.6
V
Maximum value valid for
operation up to 24h
accumulated over lifetime
in temperature range of
-25˚C ≤ Tj ≤ 125˚C.
Else the maximum value
is 3.6V.
–
IMON
VIMON
-0.3
–
3.6
V
–
IMONREF
VIMONREF
-0.3
–
3.6
V
–
Junction temperature
TJmax
-40
–
150
C
–
Storage temperature
TSTG
-55
–
150
C
–
Note: All rated voltages are relative to voltages on the CGND and PGND pins unless otherwise specified.
1
AC is limited to 10 ns
Data Sheet
8
Revision 2.4, 2015-07-16
TDA21321
Electrical Specification
Figure 4
Repetitive Voltage Stress at Phase Node - Safe Operating Area
Note: ton refers to the on-time of the HS-MOSFET. For input voltages below 10 V no limits on the
duration of ton need to be applied.
Information: a) - Area of typical computing applications with 12 V input supply voltage
Data Sheet
9
Revision 2.4, 2015-07-16
TDA21321
Electrical Specification
4.2
Table 7
Thermal Characteristics
Thermal Characteristics
Parameter
Symbol
Values
Min.
Typ.
θJC
–
3.5
–
Thermal resistance to top of package
θJCtop
θJA
–
–
3.7
Thermal resistance to ambient
–
–
4.3
Note / Test
Condition
K/W
–
Max.
Thermal resistance to case (soldering point)
14
Unit
–
Ploss = 4.5 W,
TA = 70 °C,
8 layer server board
(2 oz copper)
Recommended Operating Conditions and Electrical Characteristics2
Note: VIN =12V, VDRV = VCIN = 5 V, TA = 25 °C unless otherwise specified
Table 8
Recommended Operating Conditions
Parameter
Symbol
Values
Min.
Typ.
Unit
Note / Test Condition
Max.
Input voltage
VIN
4.5
–
16
V
–
MOSFET driver voltage
VDRV
4.5
–
8
V
–
Logic supply voltage
VCIN
4.5
–
8
Frequency of the PWM
fSW
100
–
800
Junction temperature
TjOP
-25
–
2
–
kHz
+125 °C
CCM operation with stated current sense
accuracy
–
Exposure over values of the recommended ratings for extended periods may adversely affect
the operation and reliability of the device. Min/Max values are based on empirical Cpk.
Data Sheet
10
Revision 2.4, 2015-07-16
TDA21321
Electrical Specification
Table 9
Voltage Supply And Biasing Current
Parameter
Symbol
Values
Unit Note / Test Condition
Min. Typ. Max.
UVLO VCIN
rising
VUVLO1_R
3.0
–
4.0 V
UVLO VCIN
falling
VUVLO1_F
2.6
–
3.6
UVLO VDRV
rising
VUVLO2_R
4.16 4.25 4.34 V
UVLO VDRV
falling
VUVLO2_F
3.7
UVLO BOOT
rising
VUVLOboot_R 3.88 4.05 4.22 V
UVLO BOOT
falling
VUVLOboot_F
3.5
3.8
3.63 3.76
18
–
IVDRV_1MHz
–
30
–
IC current
(control)
IC quiescent
IVCIN_O
–
1.0
–
ICIN+IDRV
–
1.2
–
Pre-Bias at
SW
VSW_0
–
120
Table 10
GL, GH and TMON/FAULT enable threshold; when UVLO
VCIN is enabled then: above threshold GL is enabled, GH
depends on UVLO BOOT, TMON/FAULT is released to
report driver temperature
GL, GH and TMON/FAULT disable threshold; when UVLO
VCIN is enabled: below threshold after 3 consecutive cycles
or 15 µs (typ.) the driver outputs GL/GH are disabled,
TMON/FAULT stops temperature reporting and is held low
by pull-down resistor
3.9
–
Driver current IVDRV_600kHz
Driver enable threshold; above threshold driver is active,
driver responds to PWM input when UVLO VDRV and
UVLO BOOT are enabled, TMON/FAULT reports driver
temperature when UVLO VDRV is enabled
Driver disable threshold; below threshold driver is inactive,
PWM and TMON/FAULT held low by pull-down resistors
mA
VBOOT-VSW rising, GH enable threshold; when UVLO VCIN
and UVLO VDRV are active: above threshold GH responds
to PWM
VBOOT-VSW falling, GL/GH disable threshold; when UVLO
VCIN and UVLO VDRV are enabled: below threshold
counter starts, after 3 consecutive PWM cycles driver
outputs are disabled
OFF# = 3.3 V, fSW = 600 kHz
OFF# = 3.3 V, fSW = 1 MHz
mA
160 mV
OFF# = 3.3 V, PWM = Open for > 19 µs (typ.)
PWM in Tri-state (VPWM_S), VCIN = VDRV = 5V, internal pulldown resistor 1.5 kΩ
Current Sense
Parameter
Symbol
Values
Unit Note / Test Condition
Min. Typ. Max.
VIMON
0.8
–
2.2
IMONREF IMON gain resistor RIMON
range
Current sense gain aCS
0.2
–
1.0
-
6.67
-
ILeak
-2
0
2
IOffset
-3
0
3
µA
a11
-3
–
3
%
a12
-2.5
–
2.5
%
a13
-0.5
–
0.5
A
Corresponds to 2.25 mV at 5 mV/A
(RIMON = 750Ω), device in regulation
for 45 A < Iout < IOCPtrip tested at 25 A,
for 25 A ≤ Iout ≤ 45 A other guaranteed
by design
for -25 < Iout < 25 A
a14
-20
–
20
%
for -50 A ≤ Iout ≤ -25 A
IMON
Voltage Range
Leakage current
Current
Zero current offset
Monitoring
Accuracy at 25 °C
… 125 °C
VDRV = 5 V ± 10 %
VCIN = 5 V ± 10 %
Data Sheet
11
V
IMONREF is a current mirror output serving
kΩ as unfiltered reference node. At IMON a
filtered voltage signal proportional to the
current is provided. It tracks the average
µA/A value of IMONREF.
µA ID = 0, VCM = 1.5, PWM in tri-state
Revision 2.4, 2015-07-16
TDA21321
Electrical Specification
Table 11
Temperature Sense
Parameter
Symbol
Values
Unit Note / Test Condition
Min. Typ. Max.
Temp.
Sense
and
Accuracy
Temp. FAULT
TTMAX
140
145
Output high
VTMON_H
2.6
–
Output monitor
VTMON
0.4
–
–
3
-25
–
3
Fault delay
Temp. range
tTMONdeg
4
TTMON
Temp. coefficient
Nominal
5
TC
–
8
V25C
–
800
-4
–
Accuracy at -25 °C aTMON
… 125 °C (tested
at 25 °C, other
guaranteed by
design)
Table 12
150
°C
Temperature monitors driver junction.
–
V Circuit reports temperatures to -25 °C
accurately (0.4V). The maximum
1.8
temperature reported is TTMAX. Above TTMAX
–
µs a logic ‘H’ is asserted to indicate a fault
150
°C (latched). At OTP fault PWM input is
suspended and driver is being set to
– mV/K
tri-state mode until VCIN and/or VDRV
–
mV have been re-cycled.
4
K -25 °C … 125 °C, unspecified below -25 °C
Other Logic Functions, Inputs/Outputs And Thresholds
Parameter
Symbol
Values
Unit Note / Test Condition
OFF#
Input low
VOFF#_L
–
–
Input high
VOFF#_H
2.0
–
Input low
VPWM_L
–
–
Input high
VPWM_H
2.4
–
–
Input resistance
RIN-PWM
6
–
10
k
VPWM = 1 V
Open voltage
VPWM_O
–
1.6
–
V
VPWM_O
1.2
–
2.0
5
–
10
ns
Minimum pulse width to detect PWM pulse
PWM pulses shorter than tPWMmin will be
extended to tPWMmin
Duty cycle limitation at IOCPtrip, fault asserted and
latched after 10 truncated consecutive switching
cycles
Min. Typ. Max.
PWM
Tri-state shutdown VPWM_S
6
window
7
Min pulse width
tPWMdetect
8
0.8 V
–
VOFF# falling
VOFF# rising
0.8 V
VPWM falling
VPWM rising
–
Min pulse time
tPWMmin
–
30
–
ns
OCP
Overcurrent
Protection
IOCPtrip
58
65
72
A
HSS
High-Side-Short
Protection
VHSStrip
–
0.83
–
V
Voltage tested at phase node during LSMOSFET on-time. If voltage exceeds VHSStrip,
fault is asserted and latched.
3
Guaranteed by design
Guaranteed by design
5
Guaranteed by design
4
6
Maximum voltage range for tri-state
7
Guaranteed by design
Guaranteed by design
8
Data Sheet
12
Revision 2.4, 2015-07-16
TDA21321
Electrical Specification
Table 13
Timing Characteristics
9
Parameter
Symbol
Values
Min.
Typ.
Unit
Note / Test Condition
VOUT prebiased at 1 V,
other conditions as for
t_pts
ILOAD = 0,
VDRV = VCIN = 5 V,
VIN = 12 V,
fsw = 600 kHz
Max.
PWM tri-state to SW falling delay
t_pts2
–
16
–
ns
PWM tri-state to SW rising delay
t_pts
–
19
–
ns
PHASE Shutdown Hold-Off time from
PWM low
PHASE Shutdown Hold-Off time from
PWM high
t_tsshd
–
41
–
t_tssh
–
45
–
PWM to SW Turn-off propagation delay
t_pdlu
–
31
–
PWM to SW Turn-on propagation delay
t_pdll
–
21
–
OFF# Turn-off propagation delay falling
t_pdl_OFF#
–
17
–
OFF# Turn-on propagation delay rising
t_pdh_OFF#
–
25
–
ns
Corresponding diagrams can be found under section “Gate Driver Timing Diagram”.
9
All timing data are guaranteed by design
Data Sheet
13
Revision 2.4, 2015-07-16
TDA21321
Theory of Operation
5
Theory of Operation
The TDA21321 features a power stage with MOSFET driver. Temperature and current are being monitored.
Data and various fault conditions can be reported to the controller.
The power MOSFETs are optimized for 5 V gate drive enabling excellent high load and light load efficiency. The
gate driver is a robust high-performance driver rated at the switching node for DC voltages ranging from -1 V to
+18 V.
5.1
Driver Characteristics
The gate driver has 2 voltage inputs, VCIN and VDRV. VCIN is the 5 V logic supply for the driver. VDRV sets
the driving voltage for the high-side and low-side MOSFETs. The reference for the gate driver control circuit
(VCIN) is CGND. To decouple the sensitive control circuitry (logic supply) from a noisy environment a ceramic
capacitor must be placed between VCIN and CGND close to the pins. VDRV needs also to be decoupled using
a ceramic capacitor (MLCC) between VDRV and PGND in close proximity to the pins. PGND serves as
reference for the power circuitry including the driver output stage.
5.2
Power-Up Sequence
Without the logic supply VCIN the device remains off. PWM is held low by an internal pull down resistor. PWM
information cannot be fed to the driver. VCIN supplies power to the driver logic. With the presence of VCIN on
power-up of the gate drive voltage VDRV, the driver and the PWM input will be enabled, the unforced PWM
level will be within its tri-state window. This signals that the driver supply voltages have cleared their respective
UVLO thresholds. TMON/FAULT reports temperature. The PWM controller is expected to wait for this to happen
before initiating PWM signals to start up the system.
Note that with VCIN and VDRV present, the switching node can rise up to VSW_0 with PWM in tri-state condition.
5.3
Inputs to the Internal Control Circuits
PWM is the control input to the IC from an external PWM controller and is compatible with 3.3 V logic. The PWM
input has tri-state functionality. When the voltage remains in the specified PWM-shutdown-window for at least
the PWM-shutdown-holdoff time t_tsshd, the operation will be suspended by keeping both MOSFET gate
outputs low. Once left open, the pin is held internally at a tri-state level of VPWM_O. The PWM signal must prevail
for at least tPWMmin to initiate a response from the driver.
The PWM threshold voltages VPMW_O, VPWM_H, VPWM_L do not vary over the wide range of VCIN supply
voltages (4.5 V to 8 V).
The OFF# pin provides a means to keep the low-side MOSFET disabled regardless of the PWM signal. It is an
active low signal. An internal pull up resistor ensures regular operation when the pin is not used.
When pulled low, the low-side MOSFET is kept in off-state. In multiphase systems the OFF# pins of all phases
may be connected together. One controller output is then able to toggle the LS-FET operation mode.
Data Sheet
14
Revision 2.4, 2015-07-16
TDA21321
Theory of Operation
Table 14
PWM and OFF# Pin Functionality, Driver Outputs
PWM logic level
High
Open (Tri-state: left floating, or high impedance)
Any
Low
Low
5.4
OFF# logic level Gate HS-FET (GH) Gate LS-FET (GL)
High
Low
Low
High or open
High
Monitoring and Protection Circuits
The TDA21321 is designed with the various protection functions. Most of these protection features require a
PWM controller that reacts properly on the assertion of a fault signal at TMON/FAULT to shutdown the circuit.
Fault assertion is latched and is being removed when VCIN and/or VDRV will be re-cycled. A reported fault is
always indicating a critical condition with high stress levels on the device and/or load that requires immediate
action in form of shutdown to prevent imminent catastrophic failure.
In multiphase regulators the TMON/FAULT outputs of the power stages will have to be connected together. The
TMON/FAULT output voltage follows the highest voltage output of any phase connected. The pull-down
capability of any TMON/FAULT output is weak so that a fault assertion of any phase will always override other
phase outputs.
5.4.1
High-Side Short Protection (HSS)
The voltage at the switching node is being monitored during the LS-MOSFET being driven in on-state. When
during that time the switching node voltage exceeds a critical threshold of VHSStrip the HSS fault is being asserted
by pulling TMON/FAULT to ‘high’. The PWM controller has to shut down the power stage to prevent
catastrophic failure. TMON/FAULT is latched and will be released when VCIN and/or VDRV will be re-cycled.
HSS can lead to a very sudden current rise that can impact voltage potentials in and in vicinity of the power
device so that early reset events could potentially occur. Therefore, it is important to always have the system
controller terminate the power supply as soon as a critical event has been reported by the power stage.
5.4.2
Thermal Protection and Temperature Monitoring
The driver monitors and reports its temperature. In multiphase systems with connected TMON/FAULT pins only
the highest temperature of any of the connected phases will be reported. The PWM controller is supposed to
react on the reported temperature with power throttling commands to the load. If the system fails to respond and
the temperature continues to rise to a value of T TMAX for at least tTMONdeg, TMON/FAULT is being pulled high to
report an Over-Temperature Fault (OTP).
TMON/FAULT is latched and will be released when VCIN and/or VDRV will be re-cycled. At OTP fault the driver
outputs will be deactivated until VCIN and/or VDRV have been re-cycled. The PWM controller is ecxpected to
shut down the power stage to prevent catastrophic failure.
Data Sheet
15
Revision 2.4, 2015-07-16
TDA21321
Theory of Operation
Figure 5
Thermal monitoring and protection
Note: Temperature reporting below TTMON_min occurs with limited accuracy. TTMON_min is being defined by the
corresponding controller detection threshold for logic ‘L’.
The reported voltage as function of temperature follows this equation:
VTMON  0.6V  8 mV
5.4.3
K
 T C 
(1)
Undervoltage Lockout (UVLO)
The power stage should not be operated when its supply voltages are out of the nominal range. UVLO
conditions occurring during power up and power down must be accommodated by proper sequencing. An UVLO
condition under normal operation can indicate a problem with the driver voltage and must be handled with a
shutdown to prevent damage to the power stage.
A primary UVLO circuit monitors VCIN. Only after having VCIN in regulation range the UVLO monitoring on
VDRV takes place. During startup UVLO on VDRV is being signaled by keeping TMON/FAULT low.
With VCIN being below VUVLO1_R at startup the driver is inactive, PWM and TMON/FAULT are held low.
When VCIN exceeds VUVLO1_R the driver becomes active, pin PWM is being enabled as input and held internally
at its tri-state level of VPWM_O. Then VDRV determines TMON/FAULT:
-
Below VUVLO2_R TMON/FAULT remains ‘low’.
- When VDRV exceeds VUVLO2_R TMON/FAULT is released and reports temperature.
- When VDRV falls below VUVLO2_F for 3 consecutive cycles or 15 µs (typ.) TMON/FAULT is being pulled ‘low’.
If at startup VCIN and/or VDRV are below their respective undervoltage lockout rising thresholds (VUVLO1_R,
VUVLO2_R) GL and GH remain disabled. Once these thresholds have been cleared, the driver provides GL output
Data Sheet
16
Revision 2.4, 2015-07-16
TDA21321
Theory of Operation
signal following PWM. When the voltage VBOOT-VSW has been exceeding VUVLOboot_R, GH is being released to
respond to PWM.
When VCIN and/or VDRV are falling below their respective undervoltage lockout falling thresholds ( VUVLO1_F,
VUVLO2_F) the driver disables its outputs GH and GL to drive the MOSFETs.
When the voltage VBOOT-VSW has been falling below VUVLOboot_F for 3 consecutive PWM cycles the driver will be
disabled.
Figure 6
5.4.4
Output Signal at TMON/Fault
BOOT - Undervoltage Protection (UVLOBOOT)
The voltage between BOOT and SW pins (boot-voltage) is being monitored when VCIN and VDRV have been
clearing their respective UVLO conditions. At startup, the LS-MOSFET gate (GL) is enabled to respond to the
PWM signal when VDRV is being active. If the voltage at the boot capacitor is insufficient to clear the VUVLOboot_R
threshold, GH remains disabled until the active LS-MOSFET has forced sufficient charge onto the boot
capacitor during the PWM “L” state. When the boot capacitor voltage exceeds VUVLOboot_R, the GH output for the
gate drive of the HS-MOSFET is enabled.
At startup and anytime when the boot voltage is below VUVLOboot_F an internal boot-error flag is set. The booterror flag is being reset when the boot voltage exceeded VUVLOboot_R.
If during the falling edge of the PWM (from ‘H’ to tri-state or from ‘H’ to ‘L’) the UVLOBOOT error flag is set, an
internal counter increases by one. When the counter reaches three, the driver outputs GH/GL are being
disabled (i.e. latched in tri-state), regardless of the PWM input.
To reset the driver and resume operation, the PWM input has to be held in tri-state for 19 µs (typ). After that, the
UVLOBOOT counter is being reset to zero and the driver performs a startup sequence as described before in
order to bring sufficient charge onto the boot capacitor.
Data Sheet
17
Revision 2.4, 2015-07-16
TDA21321
Theory of Operation
The UVLOBOOT counter is also being reset to zero whenever during the falling edge of the PWM the UVLO BOOT
error flag was not set, i.e. the error condition had been temporary for less than three consecutive instances of
the falling edge of the PWM signal.
To prevent depletion of the boot capacitor during extended time in tri-state during regular operation, a boot
refresh circuit will engage after 19 µs (typ) in consecutive tristate condition when the voltage at the boot
capacitor has fallen below VUVLOboot_F. This circuit remains active until VUVLOboot_R has been reached or the PWM
input signal leaves the region of tri-state. The boot refresh circuit is powered by VIN. To ensure full effectiveness
the voltage difference (VIN-VSW ) should be more than 4.8 V.
If the driver was disabled due to an UVLOBOOT error, it will be reset to resume operation when VCIN and/or
VDRV will be re-cycled or PWM will be held at tri-state level for more than 19 μs (typ).
In case of an UVLOBOOT error it is expected that the system controller discovers a missing phase, phase current
mismatch, excessive temperature or OCP events on other phases and initiates shutdown.
5.4.5
Current Monitoring and Overcurrent Protection (OCP)
The TDA21321 senses and reports current back to the controller via the voltage at IMON. This voltage is a
filtered representation of the voltage at IMONREF. IMONREF is a current source output:
I IMONREF  I OUT  aCS
(2)
The voltage at IMONREF depends on the impedance its current is being passed through. A recommended
target voltage at zero output current is 1.5V (common mode voltage). The series resistor RIMONREF between
IMONREF and the common mode voltage reference sets the voltage gain of the current sense according to:
VIMONREF  VIMONREF _ CM  RIMONREF  I MONREF
(3)
The output current is now represented by the voltage difference between IMON and V IMONREF_CM. VIMONREF_CM is
the voltage at IMONREF when the load current is zero.
VIMON  VIMONREF _ CM  I OUT  RIMONREF  aCS
(4)
acs is given in Table 10 for VDRV = 5V. If VDRV has been chosen to be different, acs has to be calculated as:
aCS  6.67 A
A
 1  VDRV V   5  0.012
(5)
A filter capacitor CIMON of 10 pF has to be placed between IMON and VIMONREF_CM (reference voltage pin of
RIMONREF). CIMON and RIMONREF have to be arranged in a tight loop close to the pins of the TDA21321. An
additional resistor RIMON has to be connected in parallel to CIMON. Its location is flexible and can also be at the
controller. The value for RIMON should be chosen identical to RIMONREF within the range of 200 Ω to 1 kΩ.
At the voltage receiver side the measurement loop has to be closed. It is important to not inject noise into this
loop. Therefore differential routing of IMON and IMONREF is required.
Data Sheet
18
Revision 2.4, 2015-07-16
TDA21321
Theory of Operation
For example, having a permissible 500 mV voltage range at the receiver side to report positive current of 100 A,
the resistor that has to be used in the IMONREF path can be calculated as:
VIMON  VIMONREF _ CM  500mV
RIMONREF 
VIMON  VIMONREF _ CM
I OUT  aCS

(6)
500mV
 750
100 A  6.67  10 6
Having a resistor value of 348 Ω will result in the following voltage difference:
VIMON  VIMONREF _ CM  RIMONREF  I OUT  aCS  348  100 A  6.67  106  232mV
(7)
The sensing of current occurs in the HS-MOSFET and the LS-MOSFET during their respective on-times. During
tri-state condition both MOSFETs are in off-state without sensing. The current reported is then zero. If the tristate condition was present for more than 19 µs (typ.), current reporting resumes with a delay of 1 µs (typ.).
OCP: By design of the application the current should never exceed the OCP tripping threshold I OCPtrip. The duty
cycle is being truncated by the TDA21321 when the current exceeds IOCPtrip. This prevents the part from being
destroyed by excessive current. A counter is being increased counting consecutive PWM duty cycle truncations.
The counter is being reset at the first non-truncated PWM duty cycle. When the counter reaches the value of 10,
a fault will be reported at TMON/FAULT by pulling it to ‘high’ level signaling the PWM controller the need for
immediate action to prevent catastrophic failure. This fault is latched and will be released when VCIN and/or
VDRV are being re-cycled.
5.4.6
Shoot Through Protection
The TDA21321 driver includes gate drive functionality to protect against shoot through. In order to protect the
power stage from overlap, both high-side and low-side MOSFETs being on at the same time, the adaptive
control circuitry monitors specific voltages. When the PWM signal transitions to low, the high-side MOSFET will
begin to turn-off after the propagation delay time t_pdlu. When VGS of the high-side MOSFET is discharged
below 1 V (a threshold below which the high-side MOSFET is off), a secondary delay t_pdhl is initiated. After
that delay the low-side MOSFET turns on regardless of the state of the “PHASE” pin. It ensures that the
converter can sink current efficiently and the bootstrap capacitor will be refreshed appropriately during each
switching cycle. See Figure 9 for more detail.
Data Sheet
19
Revision 2.4, 2015-07-16
TDA21321
Application
6
Application
6.1
Implementation
Figure 7
Pin Interconnection Outline (transparent top view)
Note:
1. Pin 9 (PHASE) is internally connected to the SW pads 33-38.
2. The capacitor CTMON is used to filter noise from the TMON/FAULT connection. The capacitor has to be
placed at the input of the controller. Its value should be set between 0.1 nF and 0.5 nF.
3. RIMON should be chosen identical to RIMONREF.
4. CIMON and RIMONREF have to be arranged in a tight loop close to the pins of the TDA21321.
5. To lower the pre-bias voltage at Vout to below VSW_0, place a resistor from Vout to GND.
6. CIN should consist of a 0.1 µF and a 1 µF very close to the pins 15/16 and a 1 µF capacitor at pins 19/20. In
addition place sufficient MLCCs in relative proximity of each power stage to deliver energy for the on-time of
the HS-MOSFET.
7. The value of capacitor CBOOT should be chosen according to the corresponding application note.
Data Sheet
20
Revision 2.4, 2015-07-16
TDA21321
Application
6.2
Figure 8
Data Sheet
Typical Application
Six-phase voltage regulator - typical application (simplified schematic)
21
Revision 2.4, 2015-07-16
TDA21321
Gate Driver Timing Diagram
Gate Driver Timing Diagram
7
VPWM_H
VPWM_H
VPWM_H
Tri-State
PWM
VPWM_L
t_pdlu
t_pdll
VPWM_L
t_tsshd
t_pts
t_tssh
d
t_pts2
90% VSW
SW
10% VSW
Note: SW during entering/exiting tri-state
behaves dependend on inductor current.
Figure 9
Adaptive Gate Driver Timing Diagram
VOFF#_H
OFF#
VOFF#_L
t_pdh(OFF#)
t_pdl(OFF#)
LS-FET ‘ON’
LS-FET ‘ON’
SW
-VF
LS-FET ‘OFF’ (body diode conducting)
Note: PWM is low.
Figure 10
Data Sheet
OFF# Timing Diagram
22
Revision 2.4, 2015-07-16
TDA21321
Performance Curves – Typical Data
8
Performance Curves – Typical Data
Operating conditions (unless otherwise specified): VIN = +12 V, VCIN = VDRV = +5 V, VOUT = +1.8 V,
fSW = 750 kHz, 180nH (Delta, HCB118080D-181, DCR = 0.19 mΩ) inductor, TA = 25 °C, airflow = 200 LFM, no
heatsink. Efficiency and power loss reported herein include only TDA21321 losses.
8.1
Figure 11
Data Sheet
Driver Current versus Switching Frequency
Driver Current over Switching Frequency in CCM Operation
23
Revision 2.4, 2015-07-16
TDA21321
Performance Curves – Typical Data
8.2
Efficiency and Power Loss versus Output Voltage
Figure 12
Efficiency at VIN = 12 V, VCIN = VDRV = 5 V, fSW = 750 kHz, Parameter: VOUT
Figure 13
Power Loss at VIN = 12 V, VCIN = VDRV = 5 V, fSW = 750 kHz, Parameter: VOUT
Data Sheet
24
Revision 2.4, 2015-07-16
TDA21321
Performance Curves – Typical Data
8.3
Efficiency and Power Loss versus Input Voltage
Figure 14
Efficiency at fSW = 750 kHz, VCIN = VDRV = 5 V, VOUT = 1.8 V, Parameter: VIN
Figure 15
Power Loss at fSW = 750 kHz, VCIN = VDRV = 5 V, VOUT = 1.8 V, Parameter: VIN
Data Sheet
25
Revision 2.4, 2015-07-16
TDA21321
Performance Curves – Typical Data
8.4
Efficiency and Power Loss versus Switching Frequency
Figure 16
Efficiency at VIN = 12 V, VCIN = VDRV = 5 V, VOUT = 1.8 V, Parameter: fSW
Figure 17
Power Loss at VIN = 12 V, VCIN = VDRV = 5 V, VOUT = 1.8 V, Parameter: fSW
Data Sheet
26
Revision 2.4, 2015-07-16
TDA21321
Mechanical Drawing LG-WIQFN-38-1 (6.6x4.5x0.6 mm³)
9
Figure 18
Data Sheet
Mechanical Drawing LG-WIQFN-38-1 (6.6x4.5x0.6 mm³)
Mechanical Dimensions of Package (Top and Side View) in mm
27
Revision 2.4, 2015-07-16
TDA21321
Mechanical Drawing LG-WIQFN-38-1 (6.6x4.5x0.6 mm³)
Figure 19
Data Sheet
Mechanical Dimensions of Package (Bottom View) in mm
28
Revision 2.4, 2015-07-16
TDA21321
Mechanical Drawing LG-WIQFN-38-1 (6.6x4.5x0.6 mm³)
Figure 20
Data Sheet
Landing Pattern and Stencil Dimensions (SW on upper end) in mm
29
Revision 2.4, 2015-07-16
TDA21321
Packaging Information
10
Figure 21
Data Sheet
Packaging Information
Packaging Information in mm
30
Revision 2.4, 2015-07-16
TDA21321
Board Layout Recommendations
Board Layout Recommendations
11
The PCB (printed circuit board) layout design follows the listed industry standards:
10
-
Recommended vias: 10 mil hole with 20 mil via pad diameter, 12 mil hole with 24 mil via pad diameter
-
Minimum (typical) via to via center distance: 25 mil (30 … 35 mil)
-
Minimum feature width: 5 mil
-
Minimum (typical) clearance: 5 mil (15 … 20 mil)
Commonly, 10 mil via drill diameters are used for PCBs up to 150 mil thicknesses (usually 22 layers). For
thicker boards, 12 mil vias are recommended. To reduce voltage spikes caused by parasitic circuit inductance,
all primary decoupling capacitors for VIN, VDRV, BOOT and VCIN should be of MLCC type, X6S or X7R rated
and located at the same board side as the powerstage close to their respective pins. This is especially important
for the VIN to PGND MLCCs.
Electrical and thermal connection of the powerstage to the PCB is crucial for achieving high efficiency.
Therefore, vias in VIN and PGND pads are required in the pad areas to connect most effectively to other power
and PGND layers. Bigger value MLCC input capacitors should be placed at the bottom side of the PCB close to
the vias of the powerstage’s VIN and PGND pads. To reduce the stray inductance in the current commutation
loop it is strongly recommended to have the 2
nd
layers from the top and the bottom of the board to be monolithic
ground planes. All logic and signal connections between powerstage and controller should be embedded
between two ground layers. The routing of the current sense lines back to the controller has to be done
differentially, for example with 5 mil spacing and 10 – 15 mil distances to other potentials. If the PCB features
more than 10 layers, the passive components associated with the current sense lines should be located only at
the top side of the board. All resistors and capacitors near the powerstage should be in 0402 case size. For
minimizing distribution loss to the load and maintaining signal integrity, have multiple layers/planes in parallel
and ensure that the copper cross section for PGND is at least as big as it is for Vout.
Figure 22
10
Generic Board Design
Unit conversion: 1 mil = 25.4 μm
Data Sheet
31
Revision 2.4, 2015-07-16
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG