SP3224ECA-L [SIPEX]
3.0V to 5.5V RS-232 Transceivers with Auto On-Line㈢ Plus; 3.0V至5.5V的RS - 232收发器，带有自动导通线®加
| 型号： | SP3224ECA-L |
| 厂家： | 
SIPEX CORPORATION |
| 描述： | 3.0V to 5.5V RS-232 Transceivers with Auto On-Line㈢ Plus |
| 文件： | 总23页 (文件大小：4825K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Solved by
SP3224E-SP3227E
TM
®
3.0V to 5.5V RS-232 Transceivers with Auto On-Line Plus
FEATURES
■ 15kV ESD protected RS-232 I/O pins
■ Auto On-line Plus automatic power saving mode
■ Meets true EIA/TIA-232-F standards from +3.0V to
SHUTDOWN
VCC
READY
C1+
20
19
18
1
2
®
GND
V+ 3
Solved by
T1OUT
C1-
4
17
+5.5V power supply.
TM
R1IN
C2+
C2-
5
6
16
15
14
■ Adheres to EIA/TIA-562 for interoperability with
EIA/TIA-232 down to a +2.7V supply voltage
■ Regulated charge pump yields stable
RS-232 outputs
■ Drop-in replacement to MAX3224, ICL3224,
MAX3225, ICL3225, MAX3226, ICL3226,
MAX3227 and ICL3227
R1OUT
ONLINE
SP3224E
SP3225E
V-
7
T1IN
T2OUT
13
12
11
8
9
T2IN
R2IN
STATUS
R2OUT
10
TYPICAL APPLICATIONS
■ Diagnostic/Serial ports on
embedded applications
■ Handheld Test Equipment
■ PC related Peripherals and
Equipment
■ SP3224E and SP3225E reduced EMI with a slew
rate controlled 250kbps data rate
■ SP3226E and SP3227E- high speed data rate of
1 Mbps.
■ Available in RoHS compliant, Lead Free
Packaging
■ Battery Powered Equipment
■ Point-of-sale Equipment
■ Set-top Box
DESCRIPTION
The SP3224E/3225E are 2-driver/2-receiver devices and the SP3226E/SP3227E are 1-
driver/1-receiver devices. All are ideal for computer peripherals, point-of-sale equipment,
consumer and embedded applications. These devices use an internal high-efficiency,
charge-pump power supply that requires only 0.1µF capacitors in 3.3V operation. This
charge pump and Sipex’s driver architecture allow it to deliver compliant RS-232 perfor-
mance from a single power supply ranging from +3.0V to +5.5V. At voltages between 2.7V
and 3.0V the driver outputs are compliant with RS-562 and can interface to RS-232 over
short cables.
®
The Auto On-line Plus feature allows the device to automatically “wake-up” during a shut-
down state upon detecting activity and to enter a low power shutdown if idle. This power
saving feature functions without system intervention or modifications to software or driv-
ers.
SELECTION TABLE
All devices feature 3.0V to 5.5V power supply, 4 small charge pump capacitors, and 15kV ESD
protection.
Device
Data Rate (bps)
No. of
READY pin
Low-Power Shutdown
Package
Drivers/Receivers
®
SP3224E
SP3225E
SP3226E
SP3227E
250k
1M
2/2
2/2
1/1
1/1
Yes
Yes
Yes
Yes
Auto On-Line Plus
20 SSOP/TSSOP
20 SSOP/TSSOP
16 SSOP/TSSOP
16 SSOP/TSSOP
®
Auto On-Line Plus
®
250k
1M
Auto On-Line Plus
®
Auto On-Line Plus
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (Vcc).................................................-0.3V to + 6.0V
V+ (Note 1)................................................................-0.3V to + 7.0V
V- (Note 1).................................................................+0.3V to - 7.0V
|V+| + |V-| .................................................................................+13V
Input voltage at TTL input pins ............................-0.3V to Vcc+0.3V
RxIN......................................................................................... ±18V
Driver output (from Ground).................................................. ±13.2V
RxOUT, STATUS..................................................-0.3V to Vcc+0.3V
Short Circuit Duration, TxOUT to GND,. Continuous
Maximum junction temperature.....................................................150°C
Thermal Derating, Junction to Ambient
SSOP20..............................................................................θJA =83°C/W
TSSOP20.......................................................................θJA =110.7°C/W
SSOP16..............................................................................θJA =87°C/W
TSSOP16.......................................................................θJA =100.4°C/W
(One output at a time maximum)
Storage Temperature...............................................-65°C to +150°C
Operating Temperature SP322XECX...........................0°C to +70°C
Operating Temperature SP322XEEX........................-40°C to +85°C
Lead Temperature (soldering, 10s)....................................... +300°C
These are stress ratings only and functional operation of the device at
these ratings or any other above those indicated in the operation sections
of the specifications below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect reliability.
Note 1: V+ and V- can have maximum magnitudes of 7V, but their
absolute difference cannot exceed 13V.
ELECTRICAL SPECIFICATIONS
Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX,. Typical values are at TAMB = +25°C.
C1–C4 = 0.1µF tested at 3.3V ±10%. C1=0.047µF C2–C4 = 0.33µF tested at 5V ±10%.
Parameters
DC Characteristics
Symb
Test Conditions
Min.
Typ.
Max.
Unit
Receivers idle, TxIN = Vcc or GND,
Supply Current, Auto On-Line® Plus
ICC3
1
10
µA
ONLINE = GND, SHUTDOWN = Vcc
Note 2
Supply Current, Shutdown
Supply Current, Active
ICC2
ICC1
SHUTDOWN = GND
1
10
µA
ONLINE = SHUTDOWN = Vcc, No Load
1.5
2.0
mA
ONLINE = SHUTDOWN = VCC=3.3V,
No Load
Supply Current, Active
ICC1
0.7
1.0
mA
Driver Input and Logic Input Pins
VIH
VIH
VIL
Vcc = 3.3V
Vcc = 5.0V
2
High
2.4
Logic Input
Voltage
V
Low
0.8
Logic Threshold
Logic Input Leakage Current
Logic Input Hysteresis
VT
1.5
0.05
100
IIL
±1.0
µA
VHYS
mV
Receiver Outputs and STATUS Output
Receiver Output Voltage Low
VOL
VOH
IOUT = -1.6mA
IOUT = 1mA
0.4
V
V
Vcc
- 0.6
Receiver Output Voltage High
Note 2: Characterized, not 100% tested.
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
2
ELECTRICAL SPECIFICATIONS
Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX,. Typical values are at TAMB = +25°C.
C1–C4 = 0.1µF tested at 3.3V ±10%. C1=0.047µF C2–C4 = 0.33µF tested at 5V ±10%.
Parameters
Symb
Test Conditions
Min.
Typ.
Max.
Driver Outputs
Output Voltage Swing
VO
Output load = 3kΩ to GND
Output load = Open Circuit
VOUT = 0V
±5.0
±6.0
V
±15.0
±60
Short Circuit Current
Power-Off Impedance
mA
Ω
Vcc=V+ = V- = 0
300
10M
transmitter outputs= ±2V
Output Leakage Current
Vcc = 0 or 3V to 3.3V, VOUT
= ±12V, Drivers disabled
±25
15
µA
Receiver Inputs
Input Voltage Range
Input Threshold Low
-15
0.6
0.8
V
V
Vcc = 3.3V
Vcc = 5.0V
Vcc = 3.3V
Vcc = 5.0V
1.2
1.5
1.5
1.8
500
5
Input Threshold High
2.4
2.4
V
Input Hysteresis
mV
kΩ
Input Resistance
3
7
ESD Protection
ESD Protection for R_In, T_Out pins
Human Body Model
Human Body Model
±15
±2
kV
kV
All Other Pins
Auto On-line® Plus (ONLINE = GND, SHUTDOWN = Vcc)
Rx Input Threshold to STATUS output high
±2.7
V
V
Rx Input Threshold to STATUS output low
±0.3
15
Threshold to STATUS high
tSTH
tSTL
0.5
30
µs
µs
µs
sec
Threshold to STATUS low
Rx or Tx transition to drivers enabled
Last Rx or Tx transition to drivers disabled
tONLINE
tOFFLINE
Note 3
100
30
Note 2, 3
60
Note 3: A transmitter/receiver edge is defined as a transition through input logic thresholds.
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
3
TIMING CHARACTERISTICS
Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX,. Typical values are at TAMB = +25°C. C1–C4 =
0.1µF tested at 3.3V ±10%. C1=0.047µF C2–C4 = 0.33µF tested at 5V ±10%
Parameters
Symbol
Test Conditions
Min.
250
4
Typ.
Max.
Unit
kbps
V/µs
SP3224E and SP3226E
Maximum Data Rate
RL = 3kΩ, CL = 1000pF. One
transmitter switching.
Measurement taken from
+3.0V to -3.0V or -3.0V to +3.0V,
TAMB = 25°C
Transition -Region
Slew Rate
30
RL = 3kΩ to 7kΩ,
CL = 150pF to 1000pF
Receiver Propagation
Delay
R_IN to R_OUT,
CL = 150pF
tRPHL , tRPLH
0.22
0.2
µs
µs
Receiver Output
Enable Time
tRZH , tRZL
RL = 3kΩ, CL = 150pF
2
2
Receiver Output
Disable Time
tRHZ , tRLZ
0.2
µs
ns
Receiver Skew
|tPHL - tPLH| at 1.5V
200
Parameters
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
SP3225E and SP3227E
RL = 3kΩ, CL = 250pF. One
transmitter Switching
1000
500
kbps
kbps
Maximum Data Rate
RL = 3kΩ, CL = 1000pF. One
transmitter Switching
Measurement taken from +3.0V
to -3.0V or -3.0V to +3.0V,
TAMB=25°C
Instantaneous Slew
Rate
24
150
V/µs
RL = 3kΩ to 7kΩ,
CL = 150pF to 250pF
at zero crossing
Driver Skew
|tDPHL - tDPLH
|
75
ns
µs
Receiver Propagation
Delay
tRPHL , tRPLH
tRZH , tRZL
tRHZ , tRLZ
R_IN to R_OUT, CL = 150pF
0.20
Receiver Output
Enable Time
0.3
2
2
µs
Receiver Output
Disable Time
0.2
80
µs
ns
Receiver Skew
|tPHL - tPLH
|
at 1.5V
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
4
TYPICAL PERFORMANCE CHARACTERISTICS:CURVES
1.6
1.4
1.2
1
2.5
2
1.5
1
0.8
0.6
0.4
0.2
0
0.5
0
0
1000
2000
3000
4000
5000
0
1000
2000
3000
4000
5000
Load Capacitance (pF)
Load Capacitance (pF)
SP3225E/SP3227E Transmitter Input to
Receiver Output Propagation Delay vs.
Load Capacitance
SP3224E/SP3226E Transmitter Input to
Receiver Output Propagation Delay vs.
Load Capacitance
45
40
30
25
20
35
SRpos
30
SRavg
SRneg
25
SRneg
15
20
15
10
5
SRavg
10
SRpos
5
0
0
0
1000
2000
3000
4000
5000
0
1000
2000
3000
4000
5000
Load Capacitance (pF)
Load Capacitance (pF)
SP3225E/SP3227E Transmitter Output
Slew Rate vs. Load Capacitance
SP3224E/SP3226E Transmitter Output
Slew Rate vs. Load Capacitance
6
6
V+
V+
4
4
2
2
0
0
-2
-2
-4
-4
V-
V-
-6
-6
0
1000
2000
3000
4000
5000
0
1000
2000
3000
4000
5000
Load Capacitance (pF)
Load Capacitance (pF)
SP3224E/SP3226E Transmitter Output
Voltage vs. Load Capacitance
SP3225E/SP3227E Transmitter Output
Voltage
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
5
TYPICAL PERFORMANCE CHARACTERISTICS:CURVES
250
200
150
100
50
SP3225, 1Mbps
SP3224, 250kbps
0
0
500
1000
1500
2000
2500
3000
3500
Load Capacitance (pF)
Driver Skew
vs. Load Capacitance
30
25
20
15
10
5
SP3225, 1Mbps
SP3227
SP3224, 250kbps
SP3226
0
0
1000
2000
3000
4000
5000
Load Capacitance (pF)
Supply Current
vs. Load Capacitance
Charge Pump Turn-on Time versus Temperature
85
80
75
70
65
60
55
50
-55
-30
-5
20
45
70
95
Temperature (C)
Charge Pump Turn-On Time
vs. Temperature
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
6
TYPICAL PERFORMANCE CHARACTERISTICS: SCOPE SHOTS
SP3224E/SP3226E Waveforms
for 250kbps Clock Rate, RL=3kΩ,
CL=1000pF
SP3224E/SP3226E Charge Pump
Into Shutdown
SP3224E/SP3226E Waveforms
for 250kbps Clock Rate, RL=3kΩ,
CL=4700pF
SP3224E/SP3226E Charge Pump
Power On Time, Vcc=3.3V
SP3224E/SP3226E Charge Pump
Out of Shutdown
SP3224E/SP3226E Charge Pump
Waveforms for 250kbp Clock Rate
All Charge Pump waveforms use charge pump capacitor values C1-C4 = 0.1µF
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
7
TYPICAL PERFORMANCE CHARACTERISTICS: SCOPE SHOTS
SP3225E/SP3227E Waveforms for
1Mbps Clock Rate, RL=3KΩ,
CL=250pF
SP3224E/SP3226E C2+ Charge
Pump Waveforms, Vcc=3.3V, All
Channels switching
SP3225E/SP3227E Waveforms
for 1Mbps Clock Rate, RL=3KΩ,
CL=1000pF
SP3224E/SP3226E C2+ Charge
Pump Waveforms, Vcc=5V,
All Channels switching
SP3225E/SP3227E Waveforms
for 1Mbps Clock Rate, RL=3KΩ,
CL=50pF
SP3225E/SP3227E Charge
Pump Out of Shutdown
All Charge Pump waveforms use charge pump capacitor values C1-C4 = 0.1µF
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
8
TYPICAL PERFORMANCE CHARACTERISTICS
SP3225E/SP3227E Charge Pump
Into Shutdown
SP3225E/SP3227E Charge Pump
Waveforms, Vcc=3.3V, All Chan-
nel Switching
SP3225E/SP3227E Charge Pump
Waveforms, Vcc=5V, All Channel
Switching
SP3225E/SP3227E Charge Pump
Power On Time, Vcc=3.3V
SP3225E/SP3227E Charge Pump
Waveforms for 1Mbps Clock Rate
All Charge Pump waveforms use charge pump capacitor values C1-C4 = 0.1µF
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
9
CHARACTERIZATION CIRCUITS AND WAVEFORMS
3V
Input
RS-232
Output
0V
Generator
(see note B)
50Ω
tTHL
tTLH
CL
RL
(see note A)
VOH
VOL
3V
-3V
3V
-3V
3V
Output
SHUTDOWN
6V
tTHL or tTLH
SR=
TEST CIRCUIT
VOLTAGE WAVEFORMS
NOTES A. CL includes probe and jig capacitance
B. The pulse generator has the following characteristics: PRR= 250kbit/s, Zo=50Ω, 50% duty cycle, t ≤10ns, t ≤10ns
r
f
Figure 1. Driver Slew Rate
3V
0V
Input
1.5V
1.5V
RS-232
Output
Generator
(see note B)
50Ω
tDPLH
CL
(see note A)
tDPHL
RL
VOH
VOL
50%
3V
Output
50%
SHUTDOWN
Skew= ItDPHL- tDPLH
I
TEST CIRCUIT
VOLTAGE WAVEFORMS
NOTES A. CL includes probe and jig capacitance
B. The pulse generator has the following characteristics: PRR= 250kbit/s, Zo=50Ω, 50% duty cycle, t ≤10ns, t ≤10ns
r
f
Figure 2. Driver Propagation and Skew
3V or 0V
ONLINE
3V
0V
Input
1.5V
1.5V
RS-232
Output
Generator
(see note B)
50Ω
tRPHL
tRPLH
CL
(see note A)
VOH
VOL
50%
3V
Output
50%
SHUTDOWN
TEST CIRCUIT
VOLTAGE WAVEFORMS
Skew= ItRPHL- tRPLH
I
NOTES A. CL includes probe and jig capacitance
B. The pulse generator has the following characteristics: PRR= 250kbit/s, Zo=50Ω, 50% duty cycle, t ≤10ns, t ≤10ns
r
f
Figure 3. Receiver Propagation Delay and Skew
3V
0V
Input
1.5V
1.5V
VCC
S1
GND
3V or 0V
ONLINE
tPHZ
tPZH
RL
(51 at GND)
Output
3V or 0V
VOH
Output
0.3V
50%
CL
(see note A)
SHUTDOWN
50Ω
tPZL
(S1 at VCC)
tPLZ
(51 at VCC)
Generator
(See Note B)
0.3V
Output
50%
VOL
TEST CIRCUIT
NOTES: A CL includes probe and jig capacitance
B. The pulse generator has the folowing characteristics Zo=50Ω, 50% duty cycle, t ≤10ns, t ≤10ns
VOLTAGE WAVEFORMS
r
f
C. tPLZ and tPHZ are the same as tdis
D. tPZL and tPZH are the same as ten
Figure 4. Receiver Enable and Disable Times
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
10
THEORY OF OPERATION
rates fully loaded with 3KΩ in parallel with
1000pF (SP3224E/SP3226E), or 3KΩ in
parallel with 250pF (SP3225E/SP3227E)
ensuring compatibility with PC-to-PC com-
munication software. The slew rate of the
driver output on the SP3224E/SP3226E is
internally limited to a maximum of 30V/µs
in order to meet the EIA standards (EIA
RS-232D 2.1.7, Paragraph 5). The Slew
Rate of SP3225E/SP3227E is not limited
to enable higher speed data transfers. The
transition of the loaded output from HIGH
to LOW also meets the monotonic signal
transition requirements of the standard.
Description
The SP3224E and SP3225E are 2-driver/
2-receiver devices. The SP3226E and
SP3227E are 1-driver/1-receiver devices.
All are ideal for serial ports in embedded,
consumer, portable, or handheld applica-
tions. The transceivers meet the EIA/TIA-
232 and ITU-T V.28/V.24 communication
protocols for reliable serial communication.
The devices feature Sipex’s proprietary
and patented (U.S. 5,306,954) on-board
charge pump circuitry that generates ±5.5V
RS-232 voltage levels from a single +3.0V
to +5.5V power supply.
The SP3224E-SP3227E are ideal choic-
es for power sensitive designs. With the
Auto On-line Plus enabled, the SP3224E-
SP3227E reduce supply current to 1µA
whenever the transceivers are in idle. In
shutdown, the internal charge pump and
the drivers will shut down. This feature al-
lows design engineers to address power
saving concerns without major design
changes.
Receivers
The receivers convert EIA/TIA-232 signal
levels to TTL or CMOS logic output lev-
els. Receivers remain active during device
shutdown. Since receiver input is usually
from a transmission line where long cable
lengths and system interference can de-
grade the signal, the inputs have a typical
hysteresis margin of 500mV. This ensures
that the receiver is virtually immune to noisy
transmission lines. Should an input be left
unconnected, an internal 5KΩ pulldown re-
sistor to ground will commit the output of
the receiver to a HIGH state.
®
Theory Of Operation
The SP3224E-SP3227E are made up of
four basic circuit blocks: 1. Drivers, 2. Re-
ceivers, 3. the Sipex proprietary charge
®
pump, and 4. Auto On-line Plus circuitry.
Charge Pump
The charge pump is a Sipex–patented de-
sign (US Patent #5,306,954) and uses a
unique approach compared to older less-
efficient designs. The charge pump still
requires four external capacitors, but uses
a four phase voltage shifting technique to
attain symmetrical 5.5V power supplies.
The internal power supply consists of a
regulated dual charge pump that provides
output voltages 5.5V regardless of the in-
put voltage (Vcc) over the +3.0V to +5.5V
range. This is important to maintain com-
pliant RS-232 levels regardless of power
supply fluctuations.
Drivers
The drivers are inverting level transmit-
ters that convert TTL or CMOS logic lev-
els to 5.0V EIA/TIA-232 levels with an
inverted sense relative to the input logic
levels. Typically, the RS-232 output volt-
age swing is +5.4V with no load and +5V
minimum fully loaded. The driver outputs
are protected against infinite short-circuits
to ground without degradation in reliabili-
ty. These drivers comply with the EIA-TIA-
232-F and all previous RS-232 versions.
Unused driver inputs should be connected
to GND or VCC.
The charge pump operates in a discontinu-
ous mode using an internal oscillator. If the
output voltages are less than a magnitude
The drivers can guarantee output data
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
11
THEORY OF OPERATION
is identical to the first phase. The posi-
tive terminals of capacitors C1 and C2 are
charged from VCC with their negative termi-
nals initially connected to ground. C1+ is
then connected to ground and the stored
charge from C1– is superimposed onto
C2–. Since C2+ is still connected to VCC
the voltage potential across capacitor C2 is
now 2 x VCC.
of 5.5V, the charge pump is enabled. If the
output voltages exceed a magnitude of
5.5V, the charge pump is disabled. This os-
cillator controls the four phases of the volt-
age shifting. A description of each phase
follows.
Highly Efficient Charge Pump
The charge pump is used to generate posi-
tive and negative signal voltages for the
RS-232 drivers. This enables fully compli-
ant RS-232 and V.28 signals from a single
3.0 or 5.5V power supply.
Phase 4
VDD transfer: The fourth phase connects
the negative terminal of C2 to ground and
the positive terminal of C2 to the VDD stor-
age capacitor. This transfers the doubled
(V+) voltage onto C3. Meanwhile, capaci-
tor C1 charged from VCC to prepare it for
its next phase.
The charge pumps use four external capac-
itors to hold and transfer electrical charge.
The Sipex patented design (US Patent
#5,306,954) uses a unique approach com-
pared to older less efficient designs. The
pumps use a four–phase voltage shifting
technique to attain symmetrical V+ and V-
power supplies. An intelligent control oscil-
lator regulates the operation of the charge
pump to maintain the proper voltages at
maximum efficiency.
The Sipex charge pump generates V+ and
V– independently from VCC. Hence in a no-
load condition V+ and V- will be symmetri-
cal. Older charge pump approaches gen-
erate V+ and then use part of that stored
charge to generate V-. Because of inherent
losses the magnitude of V- will be smaller
than V+ on these older designs.
Phase 1
VSS charge store and double: The posi-
tive terminals of capacitors C1 and C2 are
charged from VCC with their negative termi-
nals initially connected to ground. C1+ is
then connected to ground and the stored
charge from C1– is superimposed onto
C2– . Since C2+ is still connected to VCC
the voltage potential across capacitor C2 is
now 2 x VCC.
Under lightly loaded conditions the intelli-
gent pump oscillator maximizes efficiency
by running only as needed to maintain V+
and V–. Since interface transceivers often
spend much of their time at idle this power-
efficient innovation can greatly reduce total
power consumption. This improvement is
made possible by the independent phase
sequence of the Sipex charge pump
design.
Phase 2
VSS transfer and invert: Phase two con-
nects the negative terminal of C2 to the VSS
storage capacitor and the positive terminal
of C2 to ground. This transfers the doubled
and inverted (V–) voltage onto C4. Mean-
while, capacitor C1 charged from VCC to
prepare it for its next phase.
The clock rate for the charge pump typi-
cally operates at greater than 70kHz allow-
ing the pump to run efficiently with small
0.1µF capacitors. Efficient operation de-
pends on rapidly charging and discharging
C1 and C2, therefore capacitors should be
mounted close to the IC and have low ESR
(equivalent series resistance). Inexpensive
surface mount ceramic capacitors (such as
Phase 3
VDD charge store and double: Phase three
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
12
THEORY OF OPERATION
The SP3224E-SP3227E devices have the
advanced Auto On-Line Plus feature
are widely used for power-supply decou-
pling) are ideal for use on the charge pump.
The charge pumps are designed to be able
to function properly with a wide range of
capacitor styles and values. If polarized ca-
pacitors are used the positive and negative
terminals should be connected as shown
on the Typical Operating Circuit.
®
RS-232 signals use both positive and neg-
ative voltages of greater than ±5V magni-
tude. Receivers have nominal 5kΩ imped-
ance to ground. Even when idle, drivers
will maintain output signal voltage creating
a continuous current flow. In low power,
battery operated devices this constant cur-
rent drain can decrease battery life
significantly.
Capacitance values may be increased if
operating at higher VCC or to provide great-
er stability as the capacitors age.
+
V
CC
-
Phase 2 – Vss transfer from C2 to C4.
Meanwhile C1 is charged to Vcc
+
C
+
+
+
V+
3
C
C
2
1
V
-
e
-
e
CC
Phases 1 and 3: Store/Double.
Double charge from C1 onto C2.
-
e
-
+
C2 is now charged to -2xVcc
C
4
Vss
+
C
+
+
V+
V-
3
Patented 5,306,954 (Sipex, inc.)
+
C
C
2
1
-
e
e
-
+
V
CC
C
-
4
Phase 4 VDD
transfer from C2 to C3.
Meanwhile C1 is charged to Vcc
V
e
DD
+
e
+
+
C
+
+
V+
3
C
C
1
2
-
e
V-
+
C
4
Charge Pump Phases
Minimum Recommended Charge Pump Capacitor Values
Input Voltage VCC
3.0V to 3.6V
Charge Pump Capacitor Value for SP32XX
C1-C4=0.1µF
4.5V to 5.5V
3.0V to 5.5V
C1=0.047µF, C2-C4=0.33µF
C1-C4=0.22µF
Charge Pump Capacitor Values
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
13
THEORY OF OPERATION
that saves power by turning off the charge
pumps and driver outputs when the trans-
ceiver inputs are idle for more than 30 sec-
logic LOW forces the device into shutdown
state regardless of input activity or the sta-
tus of the ONLINE pin.
®
onds. Auto On-line Plus is equivalent to
Maxim’s “Auto Shutdown Plus” feature. It
differs from our existing Auto On-line by
The STATUS output determines whether a
valid RS-232 signal voltage is present on
the inputs. The STATUS pin goes to a logic
LOW when the receiver input signal levels
collapse near reference ground. This may
occur when the RS-232 cable is discon-
nected or the RS-232 drivers of the con-
nected peripheral are turned off.
®
relying on signal transitions rather than
voltage levels to trigger shutdown and
wakeup.
®
Auto On-Line Plus automatically puts the
device into a standby mode where it draws
only 1µA typical. When the device detects
activity on either the receiver or driver in-
puts it will automatically awake and activate
to allow serial communication. Both the
wakeup and shutdown happen automati-
STATUS may be used to indicate DTR or a
Ring Indicator signal or to determine wheth-
er a live RS232 driver or cable is connect-
ed. By connecting the STATUS output to
ONLINE input, the SP3224E-SP3227E will
shut down when no valid signal level and
no input transitions are detected, and wake
up on a valid signal level or signal edge. If it
detects no signal transitions with the past 30
Receiver
5kΩ
EDGE
DETECT
+0.3V
T_IN
SHUTDOWN
S
R_IN
-0.3V
AUTO ONLINE
30s
30µs
timer
EDGE
DETECT
STATUS
timer
R_IN
A
INVALID ASSERTED IF ALL RECEIVER INPUTS ARE
BETWEEN +0.3V AND -0.3V FOR AT LEAST 30µS
ONLINE
Figure 3c. Auto On-line® Plus Logic
Figure 3a.STATUS Functional Diagram STATUS low
+2.7V
R_IN
SHUTDOWN
POWERDOWN
ONLINE
AUTO ONLINE
30µs
timer
STATUS
-2.7V
POWERDOWN IS ONLY A INTERNAL SIGNAL. IT
CONTROLS THE OPERATIONAL STATUS TO THE
TRANSMITTERS AND THE POWER SUPPLIES.
INVALID DEASSERTED IF ALL RECEIVER INPUTS ARE
BETWEEN +2.7V AND -2.7V FOR AT LEAST 30µS
Figure 3d. Powerdown Logic
Figure 3b. STATUS Functional Diagram, STATUS high.
cally, without any user intervention, special
drivers, or software modifications.
seconds, the device will go into low power
mode. By connecting the STATUS output to
both the ONLINE input and SHUTDOWN
input pins, the device enters into shutdown
when notreceivingavalidRS-232signalvoltage
input.
Wakeup and shutdown can be exter-
nally controlled by the ONLINE and
SHUTDOWN pins. When ONLINE is driv-
®
en to logic LOW, the Auto On-line Plus
function is active. Driving SHUTDOWN to
When the SP3224E-SP3227E devices are
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
14
THEORY OF OPERATION
shut down, the charge pumps are turned off.
V+ charge pump output decays to VCC,the
V- output decays to GND. The decay time
will depend on the size of capacitors used
for the charge pump. Once in shutdown, the
time required to exit the shutdown state and
have valid V+ and V- levels is typically 50µs.
When the SP3224E-SP3227E drivers and
internal charge pump are disabled, the sup-
ply current is reduced to 1µA.
Auto On-Line (existing)
Device enters low-power mode if receiver inputs see less than valid +/- 3V.
STATUS (or INVALID) signal output indicates if valid signal voltage is at
receivers.
Auto On-Line Plus (new) Device enters low-power mode if driver inputs or receiver inputs see no
transitions for 30 seconds. Return to full power mode upon any transition on
any driver input or receiver input
Shutdown occurs even if data cable is connected to an active driver, as long
as all inputs remain unchanged
STATUS (or INVALID) signal functions as before. Indicates if valid signal
voltage is present. But has no effect on shutdown
For SP3224E the EN input is replaced with a READY output. READY drives
high when charge pump achieves greater than -4V Vss (V-). Indicates “ready
to transmit.”
®
Comparison of Auto On-line Features
Operating Mode
ONLINE
SHDN
|RIN| >
±2.7V
Idle Inputs
(RxIN &
TxIN)
TxOUT
RxOUT
Forced Shutdown
Forced On-Line
X
1
0
1
X
X
X
X
Hi-Z
Active
Active
Active
Auto On-Line Plus
(Wake when active)
0
1
X
Active
Active
Hi-Z
Active
Active
Active
Active
Active
Active
Active
Auto On Line Plus
(Off-Line when idle)
0
1
X
Idle > 30s
Auto On-Line Plus
(Wake on cable)
STATUS
STATUS
STATUS
STATUS
STATUS
1
Yes
No
No
Yes
No
X
Active
Active
Hi-Z
Auto On-Line Plus
(Wake when active)
1
Active
Auto On-Line Plus
(Off-Line when idle)
1
Idle > 30s
Auto On-Line
(Wake on cable)
STATUS
STATUS
X
X
Active
Hi-Z
Auto On-Line
(Auto Shutoff)
®
Auto On-line Plus Truth Table
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
15
THEORY OF OPERATION
RECEIVER
INPUTS
INVALID
REGION
}
TRANSMITTER
INPUTS
TRANSMITTER
OUTPUTS
Vcc
0
STATUS
OUTPUT
t
TSTL
t
STH
t
t
OFFLINE
OFFLINE
t
ONLINE
t
ONLINE
Vcc
0
OUTPUT
V+
Vcc
0
V-
Auto On-Line® Plus Timing Diagram
tSTL (=30µs typ.)
tSTH (=0.4µs typ.)
tOFFLINE (=30s typ.)
tONLINE (=100µs typ.)
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
16
TYPICAL OPERATING CIRCUIT
+3.3V
0.1uF
19
Vcc
C5
3
2
C1+
C1-
V+
V-
C1
C3
0.1uF
0.1uF
4
5
6
SP3224E
SP3225E
7
C2+
C4
0.1uF
C2
0.1uF
C2-
T1IN
13
12
T1OUT 17
TTL/CMOS
INPUTS
RS-232
OUTPUTS
T2IN
T2OUT
8
R1OUT
R1IN
15
10
16
TTL/CMOS
OUTPUTS
RS-232
INPUTS
5kΩ
R2OUT
R2IN
9
5kΩ
READY
ONLINE
1
11
20
STATUS
14
SHUTDOWN
VCC
GND
18
+3.3V
15
Vcc
0.1uF
2
C5
3
7
C1+
V+
C1
C3
0.1uF
0.1uF
4
5
C1-
SP3226E
SP3227E
C2+
V-
C4
0.1uF
C2
6
0.1uF
C2-
11
T1IN
T1OUT
13
8
RS-232
OUTPUT + INPUT
TTL/CMOS
INPUT/OUTPUT
R1OUT
R1IN
5kΩ
9
10
16
1
READY
ONLINE
STATUS
12
VCC
SHUTDOWN
GND
14
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
17
PINOUT DIAGRAMS
SHUTDOWN
READY
C1+
20
19
18
1
2
VCC
Solved by
GND
T1OUT
V+ 3
TM
C1-
17
4
R1IN
16
15
14
C2+
C2-
5
6
R1OUT
ONLINE
SP3224E
SP3225E
V-
7
T1IN
T2OUT
13
12
11
8
9
T2IN
R2IN
STATUS
R2OUT
10
16
1
2
SHUTDOWN
VCC
READY
C1+
Solved by
15
14
13
12
11
TM
GND
V+ 3
4
5
6
7
8
T1OUT
ONLINE
T1IN
C1-
C2+
C2-
V-
SP3226E
SP3227E
10
9
STATUS
R1OUT
R1IN
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
18
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
19
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
20
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
21
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
22
ORDERING INFORMATION
Part number
SP3224ECA-L
SP3224ECY-L
SP3224EEA-L
SP3224EEY-L
SP3225ECA-L
SP3225ECY-L
SP3225EEA-L
SP3225EEY-L
SP3226ECA-L
SP3226ECY-L
SP3226EEA-L
SP3226EEY-L
SP3227ECA-L
SP3227ECY-L
SP3227EEA-L
SP3227EEY-L
Available in Tape on Reel
Temperature range
From 0°C to +70°C
From 0°C to +70°C
From -40°C to +85°C
From -40°C to +85°C
From 0°C to +70°C
From 0°C to +70°C
From -40°C to +85°C
From -40°C to +85°C
From 0°C to +70°C
From 0°C to +70°C
From -40°C to +85°C
From -40°C to +85°C
From 0°C to +70°C
From 0°C to +70°C
From -40°C to +85°C
From -40°C to +85°C
Package Type
Lead Free 20 pin SSOP
Lead Free 20 pin TSSOP
Lead Free 20 pin SSOP
Lead Free 20 pin TSSOP
Lead Free 20 pin SSOP
Lead Free 20 pin TSSOP
Lead Free 20 pin SSOP
Lead Free 20 pin TSSOP
Lead Free 16 pin SSOP
Lead Free 16 PIN SSOP
Lead Free 16 pin SSOP
Lead Free 16 PIN TSSOP
Lead Free 16 PIN SSOP
Lead Free 16 PIN TSSOP
Lead Free 16 PIN SSOP
Lead Free 16 PIN TSSOP
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the applica-
tion or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
Rev P 11/20/06
SP3224E-SP3227E Transceivers with Auto On-line® Plus
© 2006 Sipex Corporation
23
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