KY32xx
+3V to +5.5V RS-232 Transceivers
with POWERSAVE
General Description
The KY32xx series devices are EIA/TIA-232 and
V.28/V.24 communication interfaces achieve 1µA supply
current with KEYSEMI’s revolutionary POWERSAVE™
feature. A proprietary, high- efficiency, dual charge-
pumpregulated voltage converters and a low-dropout
transmitter
combine to
deliver
true
RS-232
performance from a single +3.0V to +5.5V supply.
These devices can operate from input voltages ranging
from +3.0V to +5.5V at the guaranteed data rate of 250k
bits/sec with enhanced electrostatic discharge (ESD)
protection in all RS232 I/O pins exceeding ±15kV
EN61000-4-2 Air Gap Discharge and ±8kV EN61000-4-
2 Contact Discharge.
The POWERSAVE proprietary function which
automatically powers down the on-chip regulated voltage
converters and driver circuits when a RS-232 cable is
disconnected from the host interface or when a
connected peripheral device is turned off. The system
turns on again when a valid level is applied to any RS-
232 receiver input.
Features
Meets EIA/TIA-232F and CCITT
V.28/V.24specifications for
V
CC
at +3.3V ±10%
and +5V ±10%
Low POWERSAVE Current:1μA
typical, 10μA max
Guaranteed Data Rate 250kbps
Extended ESD Protection for RS-232 I/O Pins
±15kV HBM
High Data Rate at 1000kbps Available on KY32xxF
Series
Applications
Battery-Powered And Hand-Held Applications
Peripherals interface
Portable Diagnostics Equipment
Terminal Adapters and POS terminals
Notebooks, Subnotebooks, and Palmtops
Industrial and Embedded PCs
Absolute Maximum Ratings
(All voltages referenced to GND.)
Supply Voltage
V
CC
....................................................
-0.3V to +6V
V+............................................................................... -0.3V to +7V
V-............................................................................... -0.3V to +7V
|V+| + |V-|...................................................................................+13V
Input Voltages
TxIN, PWRSAVE , SD , EN .......................... -0.3V to +6V
R_IN………........................................................................ ±15V
Output Voltages
TxOUT............................................................................ ±13.2V
RxOUT,
STATE ......................................
-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
TxOUT…….............................................................. Continuous
Continuous Power Dissipation (TA = +70°C)
Power Dissipation Per Package
16-pin SSOP (derate 7.20mW/°C above +70°C) …………… 584mW
16-pin nSOIC (derate 10.00mW/°C above +70°C)…………...720mW
16-pin TSSOP (derate 6.80mW/°C above +70°C) ………….. 556mW
16-pin PDIP (derate 11.20mW/°C above +70°C).......……..... 896mW
18-pin PDIP (derate 12.60mW/°C above +70°C)…………..... 962mW
20-pin PDIP (derate 12.80mW/°C above +70°C).......……..... 976mW
20-pin SSOP (derate 8.10mW/°C above +70°C) ........…….... 647mW
20-pin TSSOP (derate 7.20mW/°C above +70°C)…….……... 584mW
28-pin SSOP (derate 9.52mW/°C above +70°C)……………...762mW
28-pin TSSOP (derate 13.20mW/°C above +70°C) ........……........1W
32-pin VQFN (derate 29.4mW/°C above +70°C)…………….2352mW
Operating Temperature Range ...................................... 0°C to +70°C
Junction Temperature..............................................................+150°C
Storage Temperature Range .....................................-65°C to +150°C
Lead Temperature (soldering 10s) ...........................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may
cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other
conditions beyond those indicated in the operational sections of the
specifications is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
KY32xx Rev.2.0
KEYSEMI Proprietary Information Unauthorized Photocopy and Duplication
Prohibited © 2017 KEYSEMI All Rights Reserved
KY32xx
+3V to +5.5V RS-232 Transceivers
with POWERSAVE
Product Selection Guide
PART
KY3220E
KY3221E
KY3222E
KY3223E
KY3232E
KY1385E
KY3243E
Tx
1
1
2
2
2
2
3
Rx
1
1
2
2
2
2
5
Data Rate
(kbps)
250
250
250
250
250
250
250
Receiver
Enable
Yes
Yes
Yes
Yes
No
No
No
SHUTDOWN
Enable
Yes
Yes
Yes
Yes
No
Yes
Yes
POWER
SAVE
No
Yes
No
Yes
No
No
Yes
Number of
Pins
16
16
20
20
16
20
28,32
Package Type
SSOP, TSSOP
SSOP, TSSOP
SSOP, TSSOP,
SSOP, TSSOP
NSOIC, SSOP, TSSOP
SSOP
28-SSOP, 28-TSSOP, 32-VQFN
*High
Data Rate at 1000kbps Available on KY32xxF Series
Electrical Characteristics
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF,
TA = TMIN to TMAX, unless otherwise noted, Typical
values apply at V
CC
= +3.3V or +5.0V and T
A
= 25°C.)
Parameters
General InfolTypes
TTL Logic Input
TTL Logic Output
RS-232 Input
RS-232 Output
Charge Pump Pin
Power Pin
Charge Pump Caps
V
CC
Voltage Range
DC Characteristics
Supply Current, Power_save
disabled
Supply Current, Power_save enabled
PWRSAVE = SD = V
CC
,
TTL I/P= V
CC
/GND, RS-232 I/P=float
PWRSAVE =GND, SD = V
CC
,
TTL I/P= V
CC
/GND, RS-232 I/P=float
Supply Current, shutdown enabled
LOGIC Input
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Leakage Current
LOGIC Output
Output Voltage Low
Output voltage High
Output Leakage Current
Receiver Input
Input Voltage Range
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Resistance
Transmitter Output
Output Voltage Swing
Output Resistance
Output Short-circuit Current
Output Leakage Current
PWRSAVE = V
CC
/GND, SD =GND,
TTL I/P= V
CC
/GND, RS-232 I/P=float
3.3, 5.0
5.0
3.3
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
5.0
3.3
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
0
3.3, 5.0
0, 3.3, 5.0
0.8
2.4
2
0.3
±1
0.4
V
CC
-0.6
V
CC
-0.1
±0.05
+15
1.5
1.2
2.4
0.3
3
±5
300
±60
±25
7
V
V
V
V
µA
V
V
µA
V
V
V
V
V
kΩ
V
Ω
mA
µA
3.3, 5.0
1
µA
3.3, 5.0
1
µA
3.3, 5.0
0.5
mA
TxIN,
PWRSAVE , SD ,
EN
high ZIN
Conditions
typical
V
CC
Min
Typ
Max
Unit
RxOUT,
STATE
RxIN
TxOUT
C1P, C1N, C2P, C2N
V
CC
, V
GND
, V
DD
, V
SS
C1P, C1N, C2P, C2N
5.0
3.3
4.5
3
0.1
5.0
3.3
5.5
3.6
µF
V
V
V
IN
= V
CC
and GND
I
OUT
=1.6mA
I
OUT
=-1mA
Receiver O/P disabled, V
OUT
= V
CC
or GND
-15
0.8
0.6
V
IN
=±25V
R
L
=3-7k, all loaded
V
CC
=V
DD
=V
SS
=GND, V
OUT
=±2V
V
OUT
=GND
Transmitter disabled, V
OUT
=±12V
KY32xx Rev.2.0
KEYSEMI CORPORATION
2
KY32xx
+3V to +5.5V RS-232 Transceivers
with POWERSAVE
Timing Characteristics
Maximum Data Rate
< standard speed >
< high speed >
Transition-Region Slew Rate
< standard speed >
< high speed >
Transmitter Propatation t
PLH
Transmitter Propatation t
PHL
Transmitter Skew
Transmitter Output Enable Time
Transmitter Output Disable Time
Receiver Propagation t
PLH
Receiver Propagation t
PHL
Receiver Skew
Receiver Output Enable Time
Receiver Output Disable Time
AutoGreen Timing
Receiver I/P to
STATE
Output High
Receiver I/P to
STATE
Output Low
Power save mode to transmitter
enabled
ESD Tolerance
ESD HBM
ESD 1000-4-2 Contact
ESD 1000-4-2 Air
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
1
30
100
±15
±8
±15
µs
µs
µs
kV
kV
kV
R
L
=3-7k, C
L
=50pF-1000pF, 1 DR/RC switching
R
L
=3-7k, C
L
=50pF-1000pF, 1 DR/RC switching
R
L
=3-7k, C
L
=50pF-1000pF, 1 DR/RC switching
R
L
=3-7k, C
L
=50pF-1000pF, 1 DR/RC switching
3k+1000pF, all loaded
3k+1000pF, all loaded
t
PHL
- t
PLH
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
3.3, 5.0
250
1000
30
90
2
2
100
400
250
0.15
0.15
50
0.2
0.2
C
L
=150pF
C
L
=150pF
t
PHL
- t
PLH
kbps
kbps
V/µs
V/µs
V/µs
µs
µs
ns
ns
ns
µs
µs
ns
µs
µs
Pin Description
PIN
KY3220 KY3221 KY3222 KY3223 KY3232
16Pins
1
5
6
7
8
13
11
9
—
16Pins
1
5
6
7
8
13
11
9
—
20Pin
1
5
6
7
9, 16
8, 17
12, 13
10, 15
—
20Pins
1
5
6
7
9, 16
8, 17
12, 13
10, 15
—
16Pins
—
4
5
6
8,13
7,14
10,11
9,12
—
KY3243
28Pins
—
1
2
3
4,5,6,7,8
9,10,11
12,13,14
32Pins
—
29
30
31
1,2,3,4,5
6,7,8
10,11,12
EN
C2+
C2-
V-
R_IN
T_OUT
T_IN
R_OUT
ROUTB
STATE
( INVALID )
NAME
FUNCTION
Receiver Enable Control. Drive low for normal operation.
Drive high to force the receiver outputs into a high-Z state.
Positive terminal of inverting charge-pump capacitor
Negative terminal of inverting charge-pump capacitor
-5.5V generated by the charge pump
RS-232 Receiver Inputs
RS-232 Transmitter Outputs
TTL/CMOS Transmitter Inputs
TTL/CMOS Receiver Outputs
TTL/CMOS level, noninverting, always enabled receiver
outputs.
Output of the valid signal detector. Indicates if a valid RS-
232 level is present on receiver inputs logic “1”.
Drive low to shut down transmitters and on-board power
supply. This over- rides all automatic circuitry and
PWRSAVE
Drive high to override automatic circuitry keeping
transmitters on ( SD must be high)
Negative terminal of the voltage doubler charge-pump
capacitor
Ground
15,16,17, 13,14,15,
18,19
17,18
20
19
—
10
—
11
—
21
20
16
16
20
20
—
22
21
SD
—
4
14
12
4
14
—
4
18
14
4
18
—
3
15
23
24
25
22
23
24
PWRSAVE
C1-
GND
KY32xx Rev.2.0
KEYSEMI CORPORATION
3
KY32xx
+3V to +5.5V RS-232 Transceivers
with POWERSAVE
15
3
2
15
3
2
19
3
2
19
3
2
16
2
1
26
27
28
26
27
28
V
CC
V+
C1+
+3.0V to +5.5V Supply Voltage
+5.5V generated by the charge pump
Positive terminal of the voltage doubler charge-pump
capacitor
Truth Table
Operation Status
PWRSAVE
don’t care
don’t care
don’t’ care
don’t’ care
1
1
1
1
0
0
0
0
SD
0
0
0
0
1
1
1
1
1
1
1
1
EN
0
0
1
1
0
0
1
1
0
0
1
1
Signal at RXIN
present
not present
present
not present
present
not present
present
not present
present
not present
present
not present
STATE
1
0
1
0
1
0
1
0
1
0
1
0
T
X
OUT
tri-state
tri-state
tri-state
tri-state
active
active
active
active
active
tri-state
active
tri-state
R
X
OUT
active
active
tri-state
tri-state
active
active
tri-state
tri-state
active
active
tri-state
tri-state
Shutdown
Normal without PWRSAVE
Normal with
PWRSAVE
Detailed Description
Charge-Pump
The KY32xx’s family utilizes regulated on-chip dual
charge pumps that provides output voltages of
+5.5V(doubling charge pump) and -5.5V (inverting
charge pump), regardless of the input voltage (
V
CC
) over
the +3.0V to +5.5V range. The charge pumps operate in
a discontinuous mode: if the output voltages are less
than 5.5V, the charge pumps are enabled; if the output
voltages exceed 5.5V, the charge pumps are disabled.
Each charge pump requires a flying capacitor (C1, C2)
and a reservoir capacitor (C3, C4) to generate the V+ and
V- supplies.
RS-232 Receive
The KY32xx’s receivers convert RS-232 signals to
CMOS-logic output levels. They are contain standard
inverting receivers that three-state (except for the
KY3232, KY3243) via the EN or SD control lines.
Controlled Power-Down
The KY3220, KY3221, KY3222, KY3223 and KY3243
have a low-power shutdown mode controlled by the SD
pin. During shutdown the driver output and the switch-
capacitor regulated voltage converter are disabled with
the supply current falls to less than 1μA.The KY3221,
KY3223 and KY3243 use KEYSEMI’s patent pending
POWERSAVE circuitry to set/reset latches, which enable
the circuit shutdown function when a RS232 cable is
disconnected or when the peripheral is turned off and
reduce the power supply drain to 1μA supply current.
When a RS232 cable is connected or when the
peripheral is enabled, the devices will automatically
become active again.
RS-232 Transmitters
The transmitters are proprietary, low dropout, inverting
level translators that convert TTL/CMOS inputs to
EIA/TIA-232 output levels. Coupled with the on-chip 5.5V
supplies, these transmitters deliver ptrue RS-232 levels
over a wide range of single supply system voltages.
When SD is driven to ground, or the POWERSAVE
circuitry senses invalid voltage levels at all receiver
inputs, the transmitters are disabled and the outputs are
forced into a high- impedance state.
ESD Immunity
The KY32xx series incorporates ruggedized ESD cells
on all driver output and receiver input pins.
KY32xx Rev.2.0
KEYSEMI CORPORATION
4
KY32xx
+3V to +5.5V RS-232 Transceivers
with POWERSAVE
The ESD structure is improved for more rugged
applications and environments sensitive to electro-static
discharges and associated transients.
The improved ESD tolerance is at least +15kV without
damage nor latch-up.
The circuit models in following Figures represent the
typical ESD testing circuit.
The CS is initially charged with the DC power supply
when the first switch (SW1) is on.
Now that the capacitor is charged, the second switch
(SW2) is on while SW1 switches off.
The voltage stored in the capacitor is then applied
through RS, the current limiting resistor, onto the device
under test (DUT).
In ESD tests, the SW2 switch is pulsed so that the device
under test receives a duration of voltage.
For the Human Body Model, the current limiting resistor
(RS) and the source capacitor (CS) are 1.5kΩ and 100pF,
respectively. For IEC-61000-4-2, the current limiting
resistor (RS) and the source capacitor (CS) are 330Ω
and 150pF, respectively.
The higher CS value and lower RS value in the
IEC61000-4-2 model are more stringent than the Human
Body Model.
The larger storage capacitor injects a higher voltage to
the test point when SW2 is switched on.
The lower current limiting resistor increases the current
charge onto the test point.
There are two methods within EN61000-4-2, the Air
Discharge method and the Contact Discharge method.
With the Air Discharge Method, an ESD voltage is
applied to the equipment under test through air, which
simulates an electrically charged person ready to
connect a cable onto the rear of the system and the high
energy potential on the person discharges through an
arcing path to the rear panel of the system before he or
she even touches the system.
The Contact Discharge Method applies the ESD current
directly to the EUT.
This method was devised to reduce the unpredictability
of the ESD arc.
The discharge current rise time is constant since the
energy is directly transferred without the air-gap arc
inconsistencies.
KEYSEMI's RS232 transceivers meets and exceeds the
minimum criteria for EN61000-4-2 with ±15kV for Air Gap
Discharge and ±8kV for Contact Discharge.
KY32xx Rev.2.0
KEYSEMI CORPORATION
5
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