Si824x Class D Audio Driver with Precision Dead-Time Generator

Si824x
CLASS D AUDIO DRIVER
WI TH
P R E C I S I O N D E AD - T I M E G E N E R A T O R
Features
0.5 A peak output (Si8241)
 4.0 A peak output (Si8244)



PWM input

 High-precision linear programmable
dead-time generator

0.4 ns to 1 µs

 High latchup immunity >100 V/ns
 Up to 1500 Vrms output-output
isolation, supply voltage of ±750 V

Input to output isolation for low noise
(up to 2500 V)
Up to 8 MHz operation
Wide operating range
–40 to +125 °C
Transient immunity >45 kV/µs
RoHS-compliant
SOIC-16 narrow body
Applications

Ordering Information:
See page 25.
Class D audio amplifiers
Description
The Si824x isolated driver family combines two isolated drivers in a single
package. The Si8241/44 are high-side/low-side drivers specifically targeted at
high-power (>30 W) audio applications. Versions with peak output currents of
0.5 A (Si8241) and 4.0 A (Si8244) are available. All drivers operate with a
maximum supply voltage of 24 V.
Based on Silicon Labs' proprietary isolation technology, the Si824x audio drivers
incorporate input-to-output and output-to-output isolation, which enables leveltranslation of signals without additional external circuits as well as use of bipolar
supply voltage up to ±750 V. The Si824x audio drivers feature an integrated deadtime generator that provides highly precise control for achieving optimal THD.
These products also have overlap protection that safeguards against shootthrough current damage. The CMOS-based design also provides robust immunity
from latch-up and high-voltage transients. The extremely low propagation delays
enable faster modulation frequencies for an enhanced audio experience. The TTL
level compatible inputs with >400 mV hysteresis are available in PWM input
configuration; other options include UVLO levels of 8 V or 10 V. These products
are available in narrow body SOIC packages.
Functional Block Diagram
Pin Assignments
SOIC-16 (Narrow)
PWM
1
16
VDDA
NC
2
15
VOA
VDDI
3
14
GNDA
GNDI
4
13
NC
DISABLE
5
12
NC
DT
6
11
VDDB
NC
7
10
VOB
VDDI
8
9
Si8241/44
GNDB
Patents Pending
PWM
Isolation
VDDA
DT
VOA
GNDA
Programmable Dead
Time, Control Gating
VDDI
UVLO
Isolation
VDDB
DISABLE
VOB
GNDB
GNDI
Si8241/44
Rev. 1.0 4/14
Copyright © 2014 by Silicon Laboratories
Si824x
Si824x
2
Rev. 1.0
Si824x
TABLE O F C ONTENTS
Section
Page
1. Top-Level Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
2.1. Test Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1. Typical Performance Characteristics (0.5 Amp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2. Typical Performance Characteristics (4.0 Amp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3. Family Overview and Logic Operation During Startup . . . . . . . . . . . . . . . . . . . . . . . 17
3.4. Power Supply Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.5. Power Dissipation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
3.6. Layout Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.7. Undervoltage Lockout Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.8. Programmable Dead Time and Overlap Protection . . . . . . . . . . . . . . . . . . . . . . . . . 22
4. Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.1. Class D Digital Audio Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7. Package Outline: 16-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
8. Land Pattern: 16-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9. Top Marking: 16-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1. Si824x Top Marking (16-Pin Narrow Body SOIC) . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2. Top Marking Explanation (16-Pin Narrow Body SOIC) . . . . . . . . . . . . . . . . . . . . . . . 28
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Rev. 1.0
3
Si824x
1. Top-Level Block Diagram
VDDI
VDDA
ISOLATION
PWM
LPWM
VOA
UVLO
GNDA
DT CONTROL
&
OVERLAP
PROTECTION
DT
VDDI
VDDI
VDDB
ISOLATION
VDDI
UVLO
DISABLE
VOB
UVLO
GNDB
LPWM
GNDI
Si8241/44
Figure 1. Si8241/44 Single-Input High-Side/Low-Side Isolated Drivers
4
Rev. 1.0
Si824x
2. Electrical Specifications
Table 1. Electrical Characteristics1
4.5 V < VDDI < 5.5 V, VDDA = VDDB = 12 V or 15 V. TA = –40 to +125 °C. Typical specs at 25 °C
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
4.5
—
5.5
V
6.5
—
24
V
DC Specifications
Input-Side Power Supply
Voltage
Driver Supply Voltage
Input Supply Quiescent
Current
VDDI
Voltage between VDDA and
VDDA, VDDB GNDA, and VDDB and GNDB
(See “6. Ordering Guide” )
IDDI(Q)
Si8241/44
—
2
3
mA
IDDA(Q),
IDDB(Q)
Current per channel
—
—
3.0
mA
Input Supply Active Current
IDDI
PWM freq = 500 kHz
—
2.5
—
mA
Output Supply Active Current
IDDO
PWM freq = 500 kHz
—
3.6
—
mA
Input Pin Leakage Current
IPWM
–10
—
+10
µA dc
Input Pin Leakage Current
IDISABLE
–10
—
+10
µA dc
Logic High Input Threshold
VIH
2.0
—
—
V
Logic Low Input Threshold
VIL
—
—
0.8
V
Input Hysteresis
VIHYST
400
450
—
mV
Logic High Output Voltage
VOAH,
VOBH
IOA, IOB = –1 mA
(VDDA
/VDDB)
— 0.04
—
—
V
Logic Low Output Voltage
VOAL, VOBL
IOA, IOB = 1 mA
—
—
0.04
V
Output Short-Circuit Pulsed
Sink Current
IOA(SCL),
IOB(SCL)
Si8241, Figure 2
—
0.5
—
A
Si8244, Figure 2
—
4.0
—
A
Output Short-Circuit Pulsed
Source Current
IOA(SCH),
IOB(SCH)
Si8241, Figure 3
—
0.25
—
A
Si8244, Figure 3
—
2.0
—
A
Output Sink Resistance
RON(SINK)
Si8241
—
5.0
—

Si8244
—
1.0
—

Si8241
—
15
—

Si8244
—
2.7
—

Output Supply Quiescent
Current
Output Source Resistance
RON(SOURCE)
Notes:
1. VDDA = VDDB = 12 V for 8 V UVLO and 10 V UVLO devices.
2. The largest RDT resistor that can be used is 220 k.
Rev. 1.0
5
Si824x
Table 1. Electrical Characteristics1 (Continued)
4.5 V < VDDI < 5.5 V, VDDA = VDDB = 12 V or 15 V. TA = –40 to +125 °C. Typical specs at 25 °C
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
VDDI Undervoltage Threshold
VDDIUV+
VDDI rising
3.60
4.0
4.45
V
VDDI Undervoltage Threshold
VDDIUV–
VDDI falling
3.30
3.70
4.15
V
VDDI Lockout Hysteresis
VDDIHYS
—
250
—
mV
VDDA, VDDB Undervoltage
Threshold
VDDAUV+,
VDDBUV+
VDDA, VDDB rising
8 V Threshold
See Figure 35 on page 21.
7.50
8.60
9.40
V
10 V Threshold
See Figure 36 on page 21.
9.60
11.1
12.2
V
VDDA, VDDB Undervoltage
Threshold
VDDAUV–,
VDDBUV–
VDDA, VDDB falling
8 V Threshold
See Figure 35 on page 21.
7.20
8.10
8.70
V
10 V Threshold
See Figure 36 on page 21.
9.40
10.1
10.9
V
VDDA, VDDB
Lockout Hysteresis
VDDAHYS,
VDDBHYS
UVLO voltage = 8 V
—
600
—
mV
VDDA, VDDB
Lockout Hysteresis
VDDAHYS,
VDDBHYS
UVLO voltage = 10 V
—
1000
—
mV
—
10
—
ns
—
25
60
ns
—
1.0
5.60
ns
See Figures 37 and 38
0.4
—
1000
ns
CL = 1 nF (Si8241)
—
—
20
ns
CL = 1 nF (Si8244)
—
—
12
ns
AC Specifications
Minimum Pulse Width
Propagation Delay
Pulse Width Distortion
|tPLH - tPHL|
tPHL, tPLH
CL = 1 nF
PWD
Programmed Dead Time2
DT
Output Rise and Fall Time
tR,tF
Shutdown Time from
Disable True
tSD
—
—
60
ns
tRESTART
—
—
60
ns
Restart Time from
Disable False
Device Start-up Time
tSTART
Time from VDD_ = VDD_UV+
to VOA, VOB = VIA, VIB
—
5
7
µs
Common Mode
Transient Immunity
CMTI
VIA, VIB, PWM = VDDI or 0 V
VCM = 1500 V (see Figure 4)
25
45
—
kV/µs
Notes:
1. VDDA = VDDB = 12 V for 8 V UVLO and 10 V UVLO devices.
2. The largest RDT resistor that can be used is 220 k.
6
Rev. 1.0
Si824x
2.1. Test Circuits
Figures 2 and 3 depict sink current and source current test circuits.
VDDA = VDDB = 15 V
VDDI
VDD
IN
INPUT
10
OUT
Si824x
SCHOTTKY
VSS
1 µF
1 µF
CER
Measure
100 µF
8V
+
_
5.5 V
+
_
10 µF
EL
RSNS
0.1
50 ns
VDDI
GND
200 ns
INPUT WAVEFORM
Figure 2. IOL Sink Current Test Circuit
VDDA = VDDB = 15 V
VDDI
IN
INPUT
VDD
Si824x
10
OUT
SCHOTTKY
VSS
1 µF
1 µF
CER
Measure
100 µF
10 µF
EL
RSNS
0.1
50 ns
VDDI
GND
200 ns
INPUT WAVEFORM
Figure 3. IOH Source Current Test Circuit
Rev. 1.0
7
Si824x
12 V
Supply
Si824x
Input Signal
Switch
5V
Isolated Supply
VDDI
VDDA
INPUT
VOA
DISABLE
DT
GNDA
VDDB
Oscilloscope
VOB
100k
GNDI
GNDB
Isolated Ground
Input
High Voltage
Differential
Probe
Output
Vcm Surge
Output
High Voltage
Surge Generator
Figure 4. Common Mode Transient Immunity Test Circuit
Table 2. Regulatory Information*
CSA
The Si824x is certified under CSA Component Acceptance Notice 5A. For more details, see File 232873.
61010-1: Up to 300 VRMS reinforced insulation working voltage; up to 600 VRMS basic insulation working voltage.
60950-1: Up to 300 VRMS reinforced insulation working voltage; up to 600 VRMS basic insulation working voltage.
VDE
The Si824x is certified according to IEC 60747-5-2. For more details, see File 5006301-4880-0001.
60747-5-2: Up to 560 Vpeak for basic insulation working voltage.
UL
The Si824x is certified under UL1577 component recognition program. For more details, see File E257455.
Rated up to 2500 VRMS isolation voltage for basic protection.
*Note: Regulatory Certifications apply to 2.5 kVRMS rated devices, which are production tested to 3.0 kVRMS for 1 sec.
For more information, see "6.Ordering Guide" on page 25.
8
Rev. 1.0
Si824x
Table 3. Insulation and Safety-Related Specifications
Value
Parameter
Symbol
Test Condition
NBSOIC-16
2.5 kVRMS
Unit
Nominal Air Gap
(Clearance)1
L(1O1)
4.01
mm
Nominal External Tracking (Creepage)1
L(1O2)
4.01
mm
0.011
mm
600
V
Minimum Internal Gap
(Internal Clearance)
Tracking Resistance
(Proof Tracking Index)
PTI
Erosion Depth
ED
0.019
mm
Resistance
(Input-Output)2
RIO
1012

Capacitance
(Input-Output)2
CIO
1.4
pF
4.0
pF
Input Capacitance3
IEC60112
f = 1 MHz
CI
Notes:
1. The values in this table correspond to the nominal creepage and clearance values as detailed in “7. Package Outline:
16-Pin Narrow Body SOIC” . VDE certifies the clearance and creepage limits as 4.7 mm minimum for the NB SOIC-16.
UL does not impose a clearance and creepage minimum for component level certifications. CSA certifies the clearance
and creepage limits as 3.9 mm minimum for the NB SOIC 16.
2. To determine resistance and capacitance, the Si824x is converted into a 2-terminal device. Pins 1–8 are shorted
together to form the first terminal and pins 9–16 are shorted together to form the second terminal. The parameters are
then measured between these two terminals.
3. Measured from input pin to ground.
Table 4. IEC 60664-1 (VDE 0884 Part 2) Ratings
Parameter
Basic Isolation Group
Installation Classification
Test Conditions
Material Group
Specification
NB SOIC-16
I
Rated Mains Voltages < 150 VRMS
I-IV
Rated Mains Voltages < 300 VRMS
I-III
Rated Mains Voltages < 400 VRMS
I-II
Rated Mains Voltages < 600 VRMS
I-II
Rev. 1.0
9
Si824x
Table 5. IEC 60747-5-2 Insulation Characteristics*
Parameter
Symbol
Maximum Working Insulation Voltage
VIORM
Characteristic
NB SOIC-16
Unit
560
V peak
VPR
Method b1
(VIORM x 1.875 = VPR,
100%
Production Test, tm = 1 sec,
Partial Discharge < 5 pC)
1050
V peak
VIOTM
t = 60 sec
4000
V peak
Input to Output Test Voltage
Transient Overvoltage
Test Condition
Pollution Degree
(DIN VDE 0110, Table 1)
2
Insulation Resistance at TS,
VIO = 500 V
>109
RS

*Note: Maintenance of the safety data is ensured by protective circuits. The Si824x provides a climate classification of
40/125/21.
Table 6. IEC Safety Limiting Values1
Parameter
Case Temperature
Symbol
Test Condition
TS
Safety Input Current
IS
Device Power Dissipation2
PD
JA = 105 °C/W (NB SOIC-16),
VDDI = 5.5 V,
VDDA = VDDB= 24 V,
TJ = 150 °C, TA = 25 °C
NB SOIC-16
Unit
150
°C
50
mA
1.2
W
Notes:
1. Maximum value allowed in the event of a failure. Refer to the thermal derating curve in Figure 5.
2. The Si82xx is tested with VDDI = 5.5 V, VDDA = VDDB = 24 V, TJ = 150 ºC, CL = 100 pF, input 2 MHz 50% duty cycle
square wave.
10
Rev. 1.0
Si824x
Table 7. Thermal Characteristics
Parameter
Symbol
NB
SOIC-16
Unit
JA
105
°C/W
Safety-Limiting Current (mA)
IC Junction-to-Air
Thermal Resistance
60
50
VDDI = 5.5 V
VDDA, VDDB = 24 V
40
30
20
10
0
0
50
100
150
Case Temperature (ºC)
200
Figure 5. NB SOIC-16, Thermal Derating Curve, Dependence of Safety Limiting Values with Case
Temperature per DIN EN 60747-5-2
Table 8. Absolute Maximum Ratings1
Parameter
Symbol
Min
Typ
Max
Units
TSTG
–65
—
+150
°C
TA
–40
—
+125
°C
Input-side Supply Voltage
VDDI
–0.6
—
6.0
V
Driver-side Supply Voltage
VDDA, VDDB
–0.6
—
30
V
VIN
–0.5
—
VDD + 0.5
V
IO
—
—
10
mA
Storage Temperature2
Ambient Temperature under Bias
Voltage on any Pin with respect to Ground
Output Drive Current per Channel
Lead Solder Temperature (10 sec)
—
—
260
°C
3
—
—
100
V/ns
Maximum Isolation (Input to Output)
—
—
2500
VRMS
Maximum Isolation (Output to Output)
—
—
1500
VRMS
Latchup Immunity
Notes:
1. Permanent device damage may occur if the absolute maximum ratings are exceeded. Functional operation should be
restricted to the conditions as specified in the operational sections of this data sheet. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
2. VDE certifies storage temperature from –40 to 150 °C.
3. Latchup immunity specification is for slew rate applied across GNDI and GNDA or GNDB.
Rev. 1.0
11
Si824x
3. Functional Description
The operation of an Si824x channel is analogous to that of an opto coupler and gate driver, except an RF carrier is
modulated instead of light. This simple architecture provides a robust isolated data path and requires no special
considerations or initialization at start-up. A simplified block diagram for a single Si824x channel is shown in
Figure 6.
Transmitter
Receiver
Driver
RF Oscillator
VDD
A
Dead
Time
Generator
Modulator
SemiconductorBased Isolation
Barrier
B
Demodulator
0.5 to 4 A
peak
Gnd
Figure 6. Simplified Channel Diagram
A channel consists of an RF Transmitter and RF Receiver separated by a semiconductor-based isolation barrier.
Referring to the Transmitter, input A modulates the carrier provided by an RF oscillator using on/off keying. The
Receiver contains a demodulator that decodes the input state according to its RF energy content and applies the
result to output B via the output driver. This RF on/off keying scheme is superior to pulse code schemes as it
provides best-in-class noise immunity, low power consumption, and better immunity to magnetic fields. See
Figure 7 for more details.
Input Signal
Modulation Signal
Output Signal
Figure 7. Modulation Scheme
12
Rev. 1.0
Si824x
3.1. Typical Performance Characteristics (0.5 Amp)
The typical performance characteristics depicted in Figures 8 through 19 are for information purposes only. Refer
to Table 1 on page 5 for actual specification limits.
VDDA Supply Current (mA)
10
Rise/Fall Time (ns)
8
Tfall
6
4
Trise
2
VDD=12V, 25°C
CL = 100 pF
7
5
12
15
18
500kHz
3
100kHz
2
1
50 kHz
0
9
21
1MHz
4
0
9
Duty Cycle = 50%
CL = 100 pF
1 Channel Switching
6
14
19
24
VDDA Supply Voltage (V)
24
VDDA Supply (V)
Figure 11. Supply Current vs. Supply Voltage
Figure 8. Rise/Fall Time vs. Supply Voltage
5
Supply Current (mA)
Propagation Delay (ns)
30
25
H-L
20
L-H
15
VDD=12V, 25°C
CL = 100 pF
12
15
18
3
VDDA = 15V,
f = 250kHz, CL = 0 pF
Duty Cycle = 50%
2 Channels Switching
2
1
-50
10
9
4
21
0
50
100
Temperature (°C)
24
VDDA Supply (V)
Figure 12. Supply Current vs. Temperature
Figure 9. Propagation Delay vs. Supply Voltage
40
35
Duty Cycle = 50%
CL = 0 pF
1 Channel Switching
3.5
Rise/Fall Time (ns)
VDDA Supply Current (mA)
4
1MHz
3
500kHz
2.5
2
100kHz
Trise
30
25
20
Tfall
15
10
5
1.5
50 kHz
9
14
19
VDD=12V, 25°C
0
1
24
VDDA Supply Voltage (V)
0.0
0.5
1.0
1.5
2.0
Load (nF)
Figure 10. Supply Current vs. Supply Voltage
Rev. 1.0
Figure 13. Rise/Fall Time vs. Load
13
Propagation Delay (ns)
Si824x
50
4
45
3.75
35
Source Current (A)
40
L-H
30
H-L
25
20
15
3.5
3.25
3
2.75
2.5
2.25
VDD=12V, 25°C
10
0.0
0.5
1.0
VDD=12V, Vout=VDD-5V
2
1.5
2.0
10
15
Load (nF)
20
25
Supply Voltage (V)
Figure 17. Output Source Current vs. Supply
Voltage
Figure 14. Propagation Delay vs. Load
25
L-H
20
Sink Current (A)
Propagation Delay (ns)
30
H-L
15
VDD=12V, Load = 200pF
10
-40
-20
0
20
40
60
80
100
120
7
6.75
6.5
6.25
6
5.75
5.5
5.25
5
4.75
4.5
4.25
4
VDD=12V, Vout=5V
-40
Temperature (°C)
-10
20
50
80
110
Temperature (°C)
Figure 15. Propagation Delay vs. Temperature
Figure 18. Output Sink Current vs. Temperature
9
3.5
3.25
Source Current (A)
Sink Current (A)
8
7
6
5
12
14
16
18
20
22
24
2.5
VDD=12V, Vout=VDD-5V
2
-40
Supply Voltage (V)
-10
20
50
80
110
Temperature (°C)
Figure 16. Output Sink Current vs. Supply
Voltage
14
2.75
2.25
VDD=12V, Vout=5V
4
10
3
Figure 19. Output Source Current vs.
Temperature
Rev. 1.0
Si824x
3.2. Typical Performance Characteristics (4.0 Amp)
The typical performance characteristics depicted in Figures 20 through 31 are for information purposes only. Refer
to Table 1 on page 5 for actual specification limits.
VDDA Supply Current (mA)
10
Rise/Fall Time (ns)
8
Tfall
6
Trise
4
2
14
Duty Cycle = 50%
CL = 100 pF
1 Channel Switching
12
10
500kHz
8
6
100kHz
4
2
50 kHz
0
9
VDD=12V, 25°C
CL = 100 pF
12
15
18
14
19
24
VDDA Supply Voltage (V)
0
9
1MHz
21
24
Figure 23. Supply Current vs. Supply Voltage
VDDA Supply (V)
10
Supply Current (mA)
Figure 20. Rise/Fall Time vs. Supply Voltage
Propagation Delay (ns)
30
25
L-H
6
VDDA = 15V,
f = 250kHz, CL = 0 pF
Duty Cycle = 50%
2 Channels Switching
4
2
0
20
-50
0
50
15
Figure 24. Supply Current vs. Temperature
10
9
12
15
18
21
40
24
35
Rise/Fall Time (ns)
VDDA Supply (V)
Figure 21. Propagation Delay vs. Supply
Voltage
14
Duty Cycle = 50%
CL = 0 pF
1 Channel Switching
12
1MHz
Trise
30
25
20
Tfall
15
10
5
10
VDD=12V, 25°C
0
8
0
500kHz
6
4
100kHz
14
19
2
3
4
5
6
7
8
9
10
Figure 25. Rise/Fall Time vs. Load
50 kHz
0
1
Load (nF)
2
9
100
Temperature (°C)
H-L
VDD=12V, 25°C
CL = 100 pF
VDDA Supply Current (mA)
8
24
VDDA Supply Voltage (V)
Figure 22. Supply Current vs. Supply Voltage
Rev. 1.0
15
Si824x
4
50
3.75
H-L
40
35
3.5
Source Current (A)
Propagation Delay (ns)
45
L-H
30
25
3.25
3
2.75
2.5
20
2.25
15
10
0
1
2
3
4
5
6
7
8
9
10
10
Load (nF)
Sink Current (A)
Propagation Delay (ns)
H-L
L-H
20
15
VDD=12V, Load = 200pF
-40
-20
0
20
40
60
80
100
120
7
6.75
6.5
6.25
6
5.75
5.5
5.25
5
4.75
4.5
4.25
4
-40
-10
20
50
80
110
Temperature (°C)
Figure 27. Propagation Delay vs. Temperature
Figure 30. Output Sink Current vs. Temperature
3.5
9
3.25
Source Current (A)
8
Sink Current (A)
25
VDD=12V, Vout=5V
Temperature (°C)
7
6
5
3
2.75
2.5
2.25
VDD=12V, Vout=5V
4
10
12
14
16
18
20
22
VDD=12V, Vout=VDD-5V
2
24
-40
Supply Voltage (V)
-10
20
50
80
110
Temperature (°C)
Figure 28. Output Sink Current vs. Supply
Voltage
16
20
Supply Voltage (V)
30
10
15
Figure 29. Output Source Current vs. Supply
Voltage
Figure 26. Propagation Delay vs. Load
25
VDD=12V, Vout=VDD-5V
2
VDD=12V, 25°C
Figure 31. Output Source Current vs.
Temperature
Rev. 1.0
Si824x
3.3. Family Overview and Logic Operation During Startup
The Si824x family of isolated drivers consists of high-side, low-side, and dual driver configurations.
3.3.1. Products
Table 9 shows the configuration and functional overview for each product in this family.
Table 9. Si824x Family Overview
Part Number
Configuration
UVLO Voltage
Programmable
Dead Time
Inputs
Peak Output
Current (A)
Si8241
High-Side/Low-Side
8 V/10 V

PWM
0.5
Si8244
High-Side/Low-Side
8 V/10 V

PWM
4.0
3.3.2. Device Behavior
Table 10 contains truth tables for the Si8241/4 families.
Table 10. Si824x Family Truth Table*
Si8241/4 (PWM Input High-Side/Low-Side) Truth Table
PWM Input
VDDI State Disable
Output
VOA
VOB
Notes
H
Powered
L
H
L
Output transition occurs after internal dead time
expires.
L
Powered
L
L
H
Output transition occurs after internal dead time
expires.
X
Unpowered
X
L
L
Output returns to input state within 7 µs of VDDI
power restoration.
X
Powered
H
L
L
Device is disabled.
*Note: This truth table assumes VDDA and VDDB are powered. If VDDA and VDDB are below UVLO, see
"3.7.2.Undervoltage Lockout" on page 20 for more information.
Rev. 1.0
17
Si824x
3.4. Power Supply Connections
Isolation requirements mandate individual supplies for VDDI, VDDA, and VDDB. The decoupling caps for these
supplies must be placed as close to the VDD and GND pins of the Si824x as possible. The optimum values for
these capacitors depend on load current and the distance between the chip and the regulator that powers it. Low
effective series resistance (ESR) capacitors, such as Tantalum, are recommended.
3.5. Power Dissipation Considerations
Proper system design must assure that the Si824x operates within safe thermal limits across the entire load range.
The Si824x total power dissipation is the sum of the power dissipated by bias supply current, internal switching
losses, and power delivered to the load. Equation 1 shows total Si824x power dissipation. In a non-overlapping
system, such as a high-side/low-side driver, n = 1.
2
2
P D = V DDI I DDI + 2  V DDO I QOUT + C int V DDO F  + 2n  C L V DDO F 
where:
P D is the total Si824x device power dissipation (W)
I DDI is the input-side maximum bias current (3 mA)
I QOUT is the driver die maximum bias current (2.5 mA)
C int is the internal parasitic capacitance (75 pF for the 0.5 A driver and 370 pF for the 4.0 A driver)
V DDI is the input-side VDD supply voltage (4.5 to 5.5 V)
V DDO is the driver-side supply voltage (10 to 24 V)
F is the switching frequency (Hz)
n is the overlap constant (max value = 2)
Equation 1.
The maximum power dissipation allowable for the Si824x is a function of the package thermal resistance, ambient
temperature, and maximum allowable junction temperature, as shown in Equation 2:
T jmax – T A
P Dmax  --------------------------ja
where:
P Dmax = Maximum Si824x power dissipation (W)
T jmax = Si824x maximum junction temperature (150 °C)
T A = Ambient temperature (°C)
ja = Si824x junction-to-air thermal resistance (105 °C/W)
F = Si824x switching frequency (Hz)
Equation 2.
Substituting values for PDmax Tjmax, TA, and ja into Equation 2 results in a maximum allowable total power
dissipation of 1.19 W. Maximum allowable load is found by substituting this limit and the appropriate datasheet
values from Table 1 on page 5 into Equation 1 and simplifying. The result is Equation 3 (0.5 A driver) and
Equation 4 (4.0 A driver), both of which assume VDDI = 5 V and VDDA = VDDB = 18 V.
–3
 10 - – 7.5  10 – 11
C L(MAX) = 1.4
------------------------F
Equation 3.
–3
 10 - – 3.7  10 – 10
C L(MAX) = 1.4
------------------------F
Equation 4.
18
Rev. 1.0
Si824x
Equation 1 and Equation 2 are graphed in Figure 32 where the points along the load line represent the package
dissipation-limited value of CL for the corresponding switching frequency.
1 6 ,0 0 0
0 .5 A D r i ve r ( p F )
4 A D r i ve r ( p F )
1 4 ,0 0 0
1 2 ,0 0 0
8 ,0 0 0
Ta = 25 °C
6 ,0 0 0
4 ,0 0 0
2 ,0 0 0
0
700
650
600
550
500
450
400
350
300
250
200
150
100
F re q u e n c y (K h z )
Figure 32. Max Load vs. Switching Frequency
20
VDDA Supply Current (mA)
Max Load (pF)
1 0 ,0 0 0
CL = 1000pF
15
10
CL = 500pF
CL = 200pF
5
VDD=15V, 25°C
0
0
200
400
600
800
1000
Switching Frequency (kHz)
Figure 33. Switching Frequency vs. Load Current
Rev. 1.0
19
Si824x
3.6. Layout Considerations
It is most important to minimize ringing in the drive path and noise on the Si824x VDD lines. Care must be taken to
minimize parasitic inductance in these paths by locating the Si824x as close to the device it is driving as possible.
In addition, the VDD supply and ground trace paths must be kept short. For this reason, the use of power and
ground planes is highly recommended. A split ground plane system having separate ground and VDD planes for
power devices and small signal components provides the best overall noise performance.
3.7. Undervoltage Lockout Operation
Device behavior during start-up, normal operation and shutdown is shown in Figure 34, where UVLO+ and UVLOare the positive-going and negative-going thresholds respectively. Note that outputs VOA and VOB default low
when input side power supply (VDDI) is not present.
3.7.1. Device Startup
Outputs VOA and VOB are held low during power-up until VDD is above the UVLO threshold for time period
tSTART. Following this, the outputs follow the states of inputs VIA and VIB.
3.7.2. Undervoltage Lockout
Undervoltage Lockout (UVLO) is provided to prevent erroneous operation during device startup and shutdown or
when VDD is below its specified operating circuits range. The input (control) side, Driver A and Driver B, each have
their own undervoltage lockout monitors.
The Si824x input side enters UVLO when VDDI < VDDIUV–, and exits UVLO when VDDI > VDDIUV+. The driver
outputs, VOA and VOB, remain low when the input side of the Si824x is in UVLO and their respective VDD supply
(VDDA, VDDB) is within tolerance. Each driver output can enter or exit UVLO independently. For example, VOA
unconditionally enters UVLO when VDDA falls below VDDAUV– and exits UVLO when VDDA rises above
VDDAUV+.
UVLO+
UVLO-
VDD HYS
VDDI
UVLO+
UVLO-
VDD HYS
VDDA
PW M
DISABLE
tSTART
tSD
tSTART
tSTART
tSD
tRESTART
tPHL
tPLH
VOA
Figure 34. Device Behavior during Normal Operation and Shutdown
20
Rev. 1.0
Si824x
3.7.3. Undervoltage Lockout (UVLO)
The UVLO circuit unconditionally drives VO low when VDD is below the lockout threshold. Referring to Figures 35
and 36, upon power up, the Si824x is maintained in UVLO until VDD rises above VDDUV+. During power down, the
Si824x enters UVLO when VDD falls below the UVLO threshold plus hysteresis (i.e., VDD < VDDUV+ – VDDHYS).
V DDUV+ (Typ)
Output Voltage (VO) 10.5
Output Voltage (VO) 10.5
V DDUV+ (Typ)
6.0
6.5
7.0
7.5
8.0
8.5
9.0
8.5
9.5 10.0
9.0
9.5
10.0 10.5 11.0 11.5 12.0 12.5
Supply Voltage (V DD - V SS) (V)
Supply Voltage (V DD - V SS) (V)
Figure 36. Si824x UVLO Response (10 V)
Figure 35. Si824x UVLO Response (8 V)
3.7.4. Control Inputs
PWM inputs are high-true, TTL level-compatible logic inputs. VOA is high and VOB is low when the PWM input is
high, and VOA is low and VOB is high when the PWM input is low.
3.7.5. Disable Input
When brought high, the DISABLE input unconditionally drives VOA and VOB low regardless of the states of input.
Device operation terminates within tSD after DISABLE = VIH and resumes within tRESTART after DISABLE = VIL.
The DISABLE input has no effect if VDDI is below its UVLO level (i.e. VOA, VOB remain low). The DISABLE input
is typically connected to external protection circuitry to unconditionally halt driver operation in the event of a fault.
Rev. 1.0
21
Si824x
3.8. Programmable Dead Time and Overlap Protection
All high-side/low-side drivers (Si8241/4) include programmable overlap protection to prevent outputs VOA and
VOB from being high at the same time. These devices also include programmable dead time, which adds a userprogrammable delay between transitions of VOA and VOB. When enabled, dead time is present on all transitions,
even after overlap recovery. The amount of dead time delay (DT) is programmed by a single resistor (RDT)
connected from the DT input to ground per Equation 5. Minimum dead time (approximately 400 ps) can be
achieved by connecting the DT pin to VDDI. Note that dead time accuracy is limited by the resistor’s (RDT)
tolerance and temperature coefficient. See Figures 37 and 38 for additional information about dead time operation.
DT  10  RDT
where:
DT = dead time (ns)
and
RDT = dead time programming resistor (k 
1000
100
900
90
800
80
700
70
Dead-time (ns)
Dead-time (ns)
Equation 5.
600
500
400
300
0
0
80
100
RDT = 2k
RDT = 1k
RDT = 0
-40
Dead-time Resistance (k:
:)
-20
0
20
40
60
80
100
120
Temperature (°C)
Figure 37. Dead Time vs.Resistance (RDT)
22
RDT = 3k
30
10
60
RDT = 4k
40
20
40
RDT = 5k
50
100
20
RDT = 6k
60
200
0
RDT = 10k
Figure 38. Dead Time vs.Temperature
Rev. 1.0
Si824x
4. Applications
The following examples illustrate typical circuit configurations using the Si824x.
4.1. Class D Digital Audio Driver
Figures 39 and 40 show the Si8241/4 controlled by a single PWM signal. Supply can be unipolar (0 to 1500 V) or
bipolar (± 750 V).
VDD2
VDDI
D1
C2
1 µF
VDDI
C1
1uF
1500 V max
VDDA
GNDI
CB
PWM
PWMOUT
GNDA
DT
RDT
CONTROLLER
Q1
VOA
Si8241/4
VDDB
VDDB
I/O
C3
10uF
DISABLE
GNDB
Q2
VOB
Figure 39. Si824x in Half-Bridge Audio Application
VDD2
VDDI
D1
C2
1 µF
VDDI
C1
1uF
+750 V max
VDDA
GNDI
CB
PWM
PWMOUT
GNDA
DT
CONTROLLER
RDT
Q1
VOA
Si8241/4
VDDB
VDDB
I/O
C3
10uF
DISABLE
GNDB
VOB
Q2
-750 V max
Figure 40. Si824x in Half-Bridge Audio Application
D1 and CB form a conventional bootstrap circuit that allows VOA to operate as a high-side driver for Q1, which has
a maximum drain voltage of 1500 V. VOB is connected as a conventional low-side driver. Note that the input side of
the Si824x requires VDD in the range of 4.5 to 5.5 V, while the VDDA and VDDB output side supplies must be
between 6.5 and 24 V with respect to their respective grounds. The boot-strap start up time will depend on the CB
cap chosen. VDD2 is usually the same as VDDB. Also note that the bypass capacitors on the Si824x should be
located as close to the chip as possible. Moreover, it is recommended that 0.1 and 10 µF bypass capacitors be
used to reduce high frequency noise and maximize performance. The D1 diode should be a fast-recovery diode; it
should be able to withstand the maximum high voltage (e.g. 1500 V) and be low-loss. See “AN486: High-Side
Bootstrap Design Using Si823x ISODrivers in Power Delivery Systems” for more details in selecting the bootstrap
cap (CB) and diode (D1).
Rev. 1.0
23
Si824x
5. Pin Descriptions
SOIC-16 (Narrow)
PWM
1
16
VDDA
NC
2
15
VOA
VDDI
3
14
GNDA
GNDI
4
13
NC
DISABLE
5
12
NC
DT
6
11
VDDB
NC
7
10
VOB
VDDI
8
9
Si8241/44
GNDB
Table 11. Si8241/44 PWM Input HS/LS Isolated Driver (SOIC-16)
Pin
Name
1
PWM
2
NC
3
VDDI
Input-side power supply terminal; connect to a source of 4.5 to 5.5 V.
4
GNDI
Input-side ground terminal.
5
24
Description
PWM input.
No connection.
DISABLE Device Disable. When high, this input unconditionally drives outputs VOA, VOB LOW. It is
strongly recommended that this input be connected to external logic level to avoid erroneous
operation due to capacitive noise coupling.
6
DT
Dead time programming input. The value of the resistor connected from DT to ground sets the
dead time between output transitions of VOA and VOB. Defaults to 1 ns dead time when connected to VDDI or left open (see "3.8.Programmable Dead Time and Overlap Protection" on
page 22).
7
NC
No connection.
8
VDDI
Input-side power supply terminal; connect to a source of 4.5 to 5.5 V.
9
GNDB
Ground terminal for Driver B.
10
VOB
11
VDDB
12
NC
No connection.
13
NC
No connection.
14
GNDA
15
VOA
16
VDDA
Driver B output (low-side driver).
Driver B power supply voltage terminal; connect to a source of 6.5 to 24 V.
Ground terminal for Driver A.
Driver A output (high-side driver).
Driver A power supply voltage terminal; connect to a source of 6.5 to 24 V.
Rev. 1.0
Si824x
6. Ordering Guide
The currently available OPNs are listed in Table 12.
Table 12. Ordering Part Numbers*
Ordering Part
Number (OPN)
Input Type
Package
Si8241BB-D-IS1
PWM
NB SOIC-16
Si8241CB-D-IS1
PWM
NB SOIC-16
Si8244BB-D-IS1
PWM
NB SOIC-16
Si8244CB-D-IS1
PWM
NB SOIC-16
Drive
Strength
Output
Isolation
Rating
(Input to
Output)
8V
0.5 A
High-Side/Low-Side
4A
UVLO
Voltage
10 V
8V
2.5 kVrms
10 V
*Note: All packages are RoHS-compliant with peak reflow temperatures of 260 °C according to the JEDEC industry standard
classifications and peak solder temperatures. Tape and reel options are specified by adding an “R” suffix to the
ordering part number. “Si” and “SI” are used interchangeably.
Rev. 1.0
25
Si824x
7. Package Outline: 16-Pin Narrow Body SOIC
Figure 41 illustrates the package details for the Si824x in a 16-pin narrow-body SOIC (SO-16). Table 13 lists the
values for the dimensions shown in the illustration.
Figure 41. 16-pin Small Outline Integrated Circuit (SOIC) Package
Table 13. Package Diagram Dimensions
Dimension
Min
Max
Dimension
Min
Max
A
—
1.75
L
0.40
1.27
A1
0.10
0.25
L2
A2
1.25
—
h
0.25
0.50
b
0.31
0.51
θ
0°
8°
c
0.17
0.25
aaa
0.10
0.25 BSC
D
9.90 BSC
bbb
0.20
E
6.00 BSC
ccc
0.10
E1
3.90 BSC
ddd
0.25
e
1.27 BSC
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to the JEDEC Solid State Outline MS-012, Variation AC.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
26
Rev. 1.0
Si824x
8. Land Pattern: 16-Pin Narrow Body SOIC
Figure 42 illustrates the recommended land pattern details for the Si824x in a 16-pin narrow-body SOIC. Table 14
lists the values for the dimensions shown in the illustration.
Figure 42. 16-Pin Narrow Body SOIC PCB Land Pattern
Table 14. 16-Pin Narrow Body SOIC Land Pattern Dimensions
Dimension
Feature
(mm)
C1
Pad Column Spacing
5.40
E
Pad Row Pitch
1.27
X1
Pad Width
0.60
Y1
Pad Length
1.55
Notes:
1. This Land Pattern Design is based on IPC-7351 pattern SOIC127P600X165-16N
for Density Level B (Median Land Protrusion).
2. All feature sizes shown are at Maximum Material Condition (MMC) and a card
fabrication tolerance of 0.05 mm is assumed.
Rev. 1.0
27
Si824x
9. Top Marking: 16-Pin Narrow Body SOIC
9.1. Si824x Top Marking (16-Pin Narrow Body SOIC)
e4
Si824YUV
YYWWTTTTTT
9.2. Top Marking Explanation (16-Pin Narrow Body SOIC)
Base Part Number
Ordering Options
Line 1 Marking:
See Ordering Guide for more
information.
Line 2 Marking:
28
Si824 = ISOdriver product series
Y = Peak output current
 1 = 0.5 A
 4 = 4.0 A
U = UVLO level
 B = 8 V; C = 10 V
V = Isolation rating
 B = 2.5 kV
YY = Year
WW = Workweek
Assigned by the Assembly House. Corresponds to the
year and workweek of the mold date.
TTTTTT = Mfg Code
Manufacturing Code from Assembly Purchase Order
form.
Rev. 1.0
Si824x
DOCUMENT CHANGE LIST
Revision 0.1 to Revision 0.2
Deleted Table 3.
Added Tables 2 through 7.
 Added Figure 5.
 Updated common-mode transient immunity
specification throughout.


Revision 0.2 to Revision 0.3
Updated Figures 2 and 3 on page 7.
 Added Figure 4 on page 8.
 Updated Table 12 on page 25.

Revision 0.3 to Revision 1.0

Updated Table 12, Ordering Part Numbers.
Added
Revision D Ordering Part Numbers.
all Ordering Part Numbers of previous
revisions.
Removed moisture sensitivity level table notes.
Removed
Rev. 1.0
29
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