INTERSIL ISL4245EIR

ISL4238E, ISL4244E, ISL4245E
®
Data Sheet
April 2004
QFN Packaged, ±15kV ESD Protected,
+2.7V to +5.5V, 10Nanoamp, 250kbps/
1Mbps, RS-232 Transceivers with
Enhanced Automatic Powerdown
Features
• Parameters Fully Specified for 10% Tolerance Supplies
and Full Industrial Temp Range
The Intersil ISL4238E/44E/45E devices are 2.7V to 5.5V
powered RS-232 transmitters/receivers which meet
ElA/TIA-232 and V.28/V.24 specifications, even at
VCC = 3.0V. Additionally, they provide ±15kV ESD protection
(IEC6100-4-2 Air Gap and Human Body Model) on
transmitter outputs and receiver inputs (RS-232 pins).
Targeted applications are PDAs, Palmtops, and notebook
and laptop computers where the low operational, and even
lower standby, power consumption is critical. Efficient onchip charge pumps, coupled with manual and enhanced
automatic powerdown functions, reduce the standby supply
current to a 10nA trickle. Tiny 5mm x 5mm Quad Flat NoLead (QFN) packaging and the use of small, low value
capacitors ensure board space savings as well. Data rates
greater than 250kbps (ISL4238E/44E)/1Mbps (ISL4245E)
are guaranteed at worst case load conditions.
The ISL424XE are 3 driver, 5 receiver (DTE) devices that,
coupled with the QFN package, provide the industry’s
smallest, lowest power complete serial port suitable for
PDAs, and laptop or notebook computers. The 5x5 QFN
requires 60% less board area than a 28 lead TSSOP, and is
nearly 20% thinner. The devices also include a noninverting
always-active receiver for “wake-up” capability.
The ISL4238E is a 5 driver, 3 receiver device optimized for
DCE applications with full hardware handshaking. It also
includes a noninverting always-active receiver for RING
INDICATOR monitoring. Transmitter and logic inputs include
active feedback resistors that retain the input state once
driven to a valid logic level.
These devices feature an enhanced automatic
powerdown function which powers down the on-chip powersupply and driver circuits. This occurs when all receiver and
transmitter inputs detect no signal transitions for a period of
30sec. These devices power back up, automatically,
whenever they sense a transition on any transmitter or
receiver input.
Table 1 summarizes the features of the ISL4238E/4XE, while
Application Note AN9863 summarizes the features of each
device comprising the 3V RS-232 family.
1
FN8038.3
• Available in Small QFN (5mm x 5mm) Package which is
60% Smaller than a 28 Lead TSSOP
• ESD Protection for RS-232 I/O Pins to ±15kV (IEC6100)
• DTE (ISL4244E/45E) and DCE (ISL4238E) Versions
• Lowest Supply Current in Powerdown . . . . . . . . . . . .10nA
• Active Feedback Resistors on TX and Logic Inputs
(ISL4238E)
• Flow Through Pinouts
• Manual and Enhanced Automatic Powerdown Features
• Guaranteed Minimum Data Rate
250kbps (ISL4238E/44E) / 1Mbps (ISL4245E)
• Latch-Up Free
• On-Chip Charge Pumps Require Only Four External
0.1µF Capacitors
• Wide Power Supply Range. . . . . . . Single +2.7V to +5.5V
• Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V
• RS-232 Compatible with VCC = 2.7V
• Pb-free Available as an Option
Applications
• Any Space Constrained System Requiring RS-232 Ports
- Battery Powered, Hand-Held, and Portable Equipment
- Laptop Computers, Notebooks
- PDAs and Palmtops, Data Cables
- Cellular/Mobile Phones, Digital Cameras, GPS
Receivers
Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices”
• Technical Brief TB379 “Thermal Characterization of
Packages for ICs”
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN Packages”
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2004. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
ISL4238E, ISL4244E, ISL4245E
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
NO. OF NO. OF
Tx.
Rx.
CONFIG.
QFN PKG.
NO. OF
MONITOR Rx.
(ROUTB)
DATA
RATE
(kbps)
Rx. ENABLE
FUNCTION?
MANUAL
POWERDOWN?
ENHANCED
AUTOMATIC
POWERDOWN
FUNCTION?
ISL4238E
5
3
DCE
5x5
1
250
NO
YES
YES
ISL4244E
3
5
DTE
5x5
1
250
NO
YES
YES
ISL4245E
3
5
DTE
5x5
1
1000
NO
YES
YES
Ordering Information
PART NO.
(BRAND)
Ordering Information (Continued)
TEMP.
RANGE (°C)
PKG.
DWG. #
PACKAGE
PART NO.
(BRAND)
TEMP.
RANGE (°C)
PKG.
DWG. #
PACKAGE
ISL4238EIR
(4238EIR)
-40 to 85
32 Ld QFN
L32.5x5
ISL4245EIR
(4245EIR)
-40 to 85
32 Ld QFN
L32.5x5
ISL4238EIRZ
(4238EIR) (Note)
-40 to 85
32 Ld QFN (Pb-free)
L32.5x5
ISL4245EIRZ
(4245EIR) (Note)
-40 to 85
32 Ld QFN (Pb-free)
L32.5x5
ISL4238EIR-T
(4238EIR)
-40 to 85
Tape & Reel
L32.5x5
ISL4245EIR-T
(4245EIR)
-40 to 85
Tape & Reel
L32.5x5
ISL4238EIRZ-T
(4238EIR) (Note)
-40 to 85
Tape & Reel (Pb-free) L32.5x5
ISL4245EIRZ-T
(4245EIR) (Note)
-40 to 85
Tape & Reel (Pb-free) L32.5x5
ISL4244EIR
(4244EIR)
-40 to 85
32 Ld QFN
L32.5x5
ISL4244EIRZ
(4244EIR) (Note)
-40 to 85
32 Ld QFN (Pb-free)
L32.5x5
ISL4244EIR-T
(4244EIR)
-40 to 85
Tape & Reel
L32.5x5
NOTE: Intersil Pb-free products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin
plate termination finish, which is compatible with both SnPb and
Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J Std-020B.
ISL4244EIRZ-T
(4244EIR) (Note)
-40 to 85
Tape & Reel (Pb-free) L32.5x5
Pinouts
VCC
NC
NC
V-
C2-
C2+
C1+
V+
VCC
NC
29
V+
30
ISL4244E, ISL4245E (QFN)
TOP VIEW
C1+
31
C2+
C2-
32
GND
V-
ISL4238E (QFN)
TOP VIEW
28
27
26
25
32
31
30
29
28
27
26
25
3
22 FORCEON
R1IN
4
21 T3IN
R4IN
4
21 FORCEOFF
R2IN
5
20 R1OUT
R5IN
5
20 INVALID
T4OUT
6
19 R2OUT
T1OUT
6
19 R2OUTB
R3IN
7
18 T4IN
T2OUT
7
18 R1OUT
T5OUT
8
17 R3OUT
T3OUT
8
17 R2OUT
9
10
11
12
13
14
15
16
9
10
11
12
13
14
15
16
NC
R3IN
R3OUT
22 T2IN
R4OUT
3
R5OUT
T3OUT
T1IN
23
T2IN
2
T3IN
R2IN
NC
23 T1IN
NC
2
T5IN
T2OUT
R1OUTB
24 GND
NC
1
INVALID
R1IN
FORCEOFF
24 C1-
FORCEON
1
NC
T1OUT
2
C1-
ISL4238E, ISL4244E, ISL4245E
Pin Descriptions
PIN
VCC
FUNCTION
System power supply input (2.7V to 5.5V).
V+
Internally generated positive transmitter supply (+5.5V).
V-
Internally generated negative transmitter supply (-5.5V).
GND
Ground connection.
C1+
External capacitor (voltage doubler) is connected to this lead.
C1-
External capacitor (voltage doubler) is connected to this lead.
C2+
External capacitor (voltage inverter) is connected to this lead.
C2-
External capacitor (voltage inverter) is connected to this lead.
TIN
TTL/CMOS compatible transmitter Inputs. (Note 1)
TOUT
RIN
ROUT
±15kV ESD Protected, RS-232 level (nominally ±5.5V) transmitter outputs.
±15kV ESD Protected, RS-232 compatible receiver inputs.
TTL/CMOS level receiver outputs.
ROUTB
TTL/CMOS level, noninverting, always enabled receiver outputs.
INVALID
Active low output that indicates if no valid RS-232 levels are present on any receiver input.
FORCEOFF Active low to shut down transmitters and on-chip power supply. This overrides any automatic circuitry and FORCEON (see Table 2).
FORCEON
Active high input to override automatic powerdown circuitry thereby keeping transmitters active. (FORCEOFF must be high).
NOTE:
1. ISL4238E input pins incorporate positive feedback resistors. Once the input is driven to a valid logic level, the feedback resistor maintains that
logic level until VCC is removed. Unused transmitter inputs may be left unconnected by the user.
3
ISL4238E, ISL4244E, ISL4245E
Typical Operating Circuits
ISL4238E
+3.3V
+
C1
0.1µF
NOTE 2
C2
0.1µF
0.1µF
28
+
24
29
+
31
C1+
26
27
VCC
+
V+
C1C2+
V-
C2-
32
23
T1
22
T2
2
21
T3
3
18
T4
6
15
T5
8
NOTE 2
C4
0.1µF
+
1
T1IN
T1OUT
T2IN
T2OUT
T3IN
T3OUT
T4IN
RS-232
LEVELS
T4OUT
T5IN
TTL/CMOS
LOGIC
LEVELS
C3
0.1µF
T5OUT
14
R1OUTB
20
4
R1OUT
R1IN
R1
5kΩ
19
5
R2OUT
R2IN
R2
5kΩ
17
RS-232
LEVELS
7
R3OUT
R3IN
R3
5kΩ
10
FORCEON
VCC
TO POWER
CONTROL
LOGIC
11
FORCEOFF
12
INVALID
GND
30
NOTE:
2. For VCC = 3.15V (3.3V -5%), use C1 - C4 = 0.1µF or greater. For VCC = 3.0V (3.3V -10%), use C1 - C4 = 0.22µF or greater.
4
ISL4238E, ISL4244E, ISL4245E
Typical Operating Circuits (Continued)
ISL4244E, ISL4245E
+3.3V
+
0.1µF
28
C1
0.1µF
+
C2
0.1µF
C129
C2+
+
30
C2-
C1+
26
VCC
23
27
VT1
12
+
V+
31
C3
0.1µF
C4
0.1µF
+
6
T1IN
T1OUT
T2
11
7
T2IN
T2OUT
T3
10
RS-232
LEVELS
8
T3IN
T3OUT
19
R2OUTB
TTL/CMOS
LOGIC LEVELS
18
1
R1OUT
R1IN
R1
5kΩ
17
2
R2OUT
R2IN
R2
5kΩ
15
3
R3OUT
R3IN
R3
5kΩ
14
4
R4OUT
R4IN
R4
5kΩ
13
5
R5OUT
R5IN
22
VCC
TO POWER
CONTROL LOGIC
5kΩ
R5
FORCEON
21
FORCEOFF
20
INVALID
GND
24
5
RS-232
LEVELS
ISL4238E, ISL4244E, ISL4245E
Absolute Maximum Ratings
Thermal Information
VCC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V
V+ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V
V- to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3V to -7V
V+ to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14V
Input Voltages
TIN, FORCEOFF, FORCEON. . . . . . . . . . . . . . . . . . . -0.3V to 6V
RIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25V
Output Voltages
TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±13.2V
ROUT, INVALID. . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC +0.3V
Short Circuit Duration
TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table
Thermal Resistance (Typical, Note 3)
θJA (oC/W)
32 Ld QFN Package. . . . . . . . . . . . . . . . . . . . . . . . .
32
Moisture Sensitivity (see Technical Brief TB363)
QFN Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Level 1
Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC
Operating Conditions
Temperature Range
ISL42XXEIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
3. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379, and Tech Brief TB389.
Test Conditions: ISL4238E VCC = 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF;
ISL424XE VCC = 3V to 5.5V, C1 - C4 = 0.1µF; Unless Otherwise Specified. Typicals are at TA = 25oC
Electrical Specifications
PARAMETER
TEST CONDITIONS
TEMP
(oC)
MIN
Full
2.7
-
5.5
V
25
-
3
300
nA
50
300
nA
TYP
MAX
UNITS
DC CHARACTERISTICS
Operating Voltage Range
Supply Current, Automatic
Powerdown
All RIN Open, FORCEON = GND, FORCEOFF = VCC
Supply Current, Powerdown
All RIN Open, FORCEOFF = GND
Full
25
-
Full
Supply Current,
Automatic Powerdown Disabled
All Outputs Unloaded, FORCEON = FORCEOFF = VCC,
VCC = 3.0V
25
-
Full
3
300
nA
50
300
nA
0.3
1.0
mA
0.3
1.5
mA
LOGIC AND TRANSMITTER INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold Low
TIN, FORCEON, FORCEOFF
Full
-
-
0.8
V
Input Logic Threshold High
TIN, FORCEON, FORCEOFF, VCC = 3.6V
Full
2.0
-
-
V
25
-
0.5
-
V
Transmitter Input Hysteresis
Input Leakage Current
TIN, FORCEON, FORCEOFF (ISL4238E, Note 4)
Full
-
±0.01
±1.0
µA
Output Leakage Current
FORCEOFF = GND
Full
-
±0.05
±10
µA
Output Voltage Low
IOUT = 1.6mA
Full
-
-
0.4
V
Output Voltage High
IOUT = -1.0mA
Full
-
V
Full
-25
-
25
V
Input Threshold Low
VCC = 3.0V
Full
-
1.0
0.6
V
Input Threshold High
VCC = 3.6V
Full
2.4
1.5
-
V
VCC -0.6 VCC -0.1
RECEIVER INPUTS
Input Voltage Range
Input Hysteresis
25
-
0.5
-
V
Input Resistance
Full
3
5
7
kΩ
TRANSMITTER OUTPUTS
Output Voltage Swing
All Transmitter Outputs Loaded with 3kΩ to Ground
Full
±5.0
±5.4
-
V
Output Resistance
VCC = V+ = V- = 0V, Transmitter Output = ±2V
Full
300
10M
-
Ω
Full
-
±35
±60
mA
VOUT = ±12V, VCC = 0V or 3V to 5.5V,
Automatic Powerdown or FORCEOFF = GND
Full
-
-
±25
µA
Output Short-Circuit Current
Output Leakage Current
6
ISL4238E, ISL4244E, ISL4245E
Test Conditions: ISL4238E VCC = 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF;
ISL424XE VCC = 3V to 5.5V, C1 - C4 = 0.1µF; Unless Otherwise Specified. Typicals are at TA = 25oC
Electrical Specifications
PARAMETER
TEST CONDITIONS
TEMP
(oC)
MIN
TYP
MAX
UNITS
ENHANCED AUTOMATIC POWERDOWN (FORCEON = GND, FORCEOFF = VCC)
Receiver Input Thresholds to
INVALID High
See Figure 6
Full
-2.7
-
2.7
V
Receiver Input Thresholds to
INVALID Low
See Figure 6
Full
-0.3
-
0.3
V
INVALID, Output Voltage Low
IOUT = 1.6mA
Full
-
-
0.4
V
INVALID, Output Voltage High
IOUT = -1.0mA
Full
VCC-0.6
-
-
V
Receiver Positive or Negative
Threshold to INVALID High Delay
(tINVH)
25
-
0.5
1
µs
Full
-
0.9
1.5
µs
25
-
60
100
µs
100
150
µs
30
50
µs
40
60
µs
Receiver Positive or Negative
Threshold to INVALID Low Delay
(tINVL)
ISL4238E
Receiver Positive or Negative
Threshold to INVALID Low Delay
(tINVL)
ISL4244E/45E
Receiver or Transmitter Edge to
Transmitters Enabled Delay (tWU)
Note 5
Full
-
20
100
µs
Receiver or Transmitter Edge to
Transmitters Disabled Delay
(tAUTOPWDN)
Note 5
Full
15
30
60
sec
Maximum Data Rate
ISL4238E/44E
RL = 3kΩ, CL = 1000pF, One Transmitter Switching
Full
250
500
-
kbps
Maximum Data Rate
ISL4245E
RL = 3kΩ, One Transmitter CL = 1000pF
Switching
VCC = 3V to 4.5V, CL = 250pF
Full
250
900
-
kbps
Full
1000
2000
-
kbps
Full
1000
1500
-
kbps
Full
25
-
Full
TIMING CHARACTERISTICS
VCC = 4.5V to 5.5V,
CL = 1000pF
Receiver Input to Receiver tPHL
Output,
CL = 150pF
tPLH
Receiver Propagation Delay
Receiver Skew
tPHL - tPLH, CL = 150pF
Transmitter Propagation Delay
ISL4238E/44E
Transmitter Input to
Transmitter Output,
CL = 1000pF, RL = 3kΩ
Transmitter Skew ISL4238E/44E
Transmitter Propagation Delay
ISL4245E
tPLH
tPHL - tPLH (Note 7), RL = 3kΩ, CL = 1000pF
Transmitter Input to
Transmitter Output,
CL = 1000pF, RL = 3kΩ
Transmitter Skew ISL4245E
tPHL
tPHL
tPLH
tPHL - tPLH (Note 6), RL = 3kΩ, CL = 1000pF
7
25
-
0.15
0.3
µs
Full
-
0.2
0.35
µs
25
-
0.3
0.5
µs
Full
-
0.35
0.55
µs
25
-
120
250
ns
Full
-
150
300
ns
25
-
0.75
1
µs
Full
-
0.85
1.1
µs
25
-
0.8
1
µs
Full
-
0.9
1.1
µs
25
-
50
200
ns
Full
-
100
250
ns
25
-
0.4
0.8
µs
Full
-
0.5
0.8
µs
25
-
0.35
0.7
µs
Full
-
0.4
0.7
µs
25
-
50
200
ns
Full
-
60
250
ns
ISL4238E, ISL4244E, ISL4245E
Test Conditions: ISL4238E VCC = 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF;
ISL424XE VCC = 3V to 5.5V, C1 - C4 = 0.1µF; Unless Otherwise Specified. Typicals are at TA = 25oC
Electrical Specifications
PARAMETER
TEST CONDITIONS
Receiver Output Enable Time
Normal Operation, RL = 1kΩ to 0.5VCC, CL = 15pF
Receiver Output Disable Time
Normal Operation, RL = 1kΩ to 0.5VCC, CL = 15pF
Transmitter Output Enable Time
ISL4238E/44E/45E
Normal Operation, RL = 3kΩ, CL = 1000pF
Transmitter Output Disable Time
ISL4238E/44E/45E
Normal Operation, RL = 3kΩ, CL = 1000pF
Transition Region Slew Rate
ISL4238E/44E
VCC = 3V to 3.6V,
RL = 3kΩ to 7kΩ,
Measured From 3V to -3V
or -3V to 3V
Transition Region Slew Rate
ISL4245E
CL = 150pF to 1000pF
CL = 150pF to 2500pF
TEMP
(oC)
MIN
TYP
MAX
UNITS
25
-
200
350
ns
Full
-
200
400
ns
25
-
350
500
ns
Full
-
400
600
ns
25
-
25
40
µs
Full
-
35
50
µs
25
-
2.5
4
µs
Full
-
2.7
4
µs
25
6
11
30
V/µs
Full
6
10
30
V/µs
25
4
9
30
V/µs
Full
4
8
30
V/µs
25
24
40
150
V/µs
Full
24
35
150
V/µs
Human Body Model
25
-
±15
-
kV
IEC6100-4-2 Air Gap Discharge
25
-
±15
-
kV
IEC6100-4-2 Contact Discharge
25
-
±8
-
kV
Human Body Model
25
-
±3
-
kV
VCC = 3V to 3.6V, RL = 3kΩ to 7kΩ, Measured From 3V to
-3V or -3V to 3V, CL = 150pF to 1000pF
ESD PERFORMANCE
RS-232 Pins (TOUT, RIN)
All Other Pins
NOTES:
4. ISL4238E inputs utilize a positive feedback resistor. The input current is negligible when the input is at either supply rail.
5. An “edge” is defined as a transition through the transmitter or receiver input thresholds.
6. Skew is measured at the receiver input switching points (1.4V).
7. Skew is measured at the transmitter zero crossing points.
Detailed Description
Transmitters
These interface ICs operate from a single +2.7V to +5.5V
supply, guarantee a 250kbps (ISL4238E/44E) / 1Mbps
(ISL4245E) minimum data rate, require only four small
external 0.1µF capacitors, feature low power consumption,
and meet all ElA RS-232C and V.28 specifications. The
circuit is divided into three sections: The charge pump, the
transmitters, and the receivers.
The transmitters are proprietary, low dropout, inverting
drivers that translate TTL/CMOS inputs to EIA/TIA-232
output levels. Coupled with the on-chip ±5.5V supplies, these
transmitters deliver true RS-232 levels over a wide range of
single supply system voltages.
Charge-Pump
Intersil’s new RS-232 family utilizes regulated on-chip dual
charge pumps as voltage doublers, and voltage inverters to
generate ±5.5V transmitter supplies from a VCC supply as
low as 3.0V. This allows these devices to maintain RS-232
compliant output levels over the ±10% tolerance range of
3.3V powered systems. The efficient on-chip power supplies
require only four small, external 0.1µF capacitors for the
voltage doubler and inverter functions. The charge pumps
operate discontinuously (i.e., they turn off as soon as the V+
and V- supplies are pumped up to the nominal values),
resulting in significant power savings.
8
Transmitter outputs disable and assume a high impedance
state when the device enters the powerdown mode (see
Table 2). These outputs may be driven to ±12V when
disabled.
The ISL4238E/44E guarantee a 250kbps data rate for full
load conditions (3kΩ and 1000pF), VCC ≥ 3.0V, with one
transmitter operating at full speed. Under more typical
conditions of VCC ≥ 3.3V, RL = 3kΩ, and CL = 250pF, one
transmitter easily operates at 1Mbps.
The ISL4245E guarantees a 1Mbps data rate for full load
conditions (3kΩ and 250pF), VCC ≥ 3.0V, with one
transmitter operating at full speed. Under more typical
conditions of VCC ≥ 3.3V, RL = 3kΩ, and CL = 250pF, one
transmitter easily operates at 1.4Mbps.
ISL4238E, ISL4244E, ISL4245E
TABLE 2. POWERDOWN LOGIC TRUTH TABLE
RCVR OR
XMTR
EDGE
WITHIN 30
SEC?
FORCEOFF FORCEON TRANSMITTER RECEIVER
ROUTB
INPUT
INPUT
OUTPUTS
OUTPUTS OUTPUTS
RS-232
LEVEL
PRESENT
AT
RECEIVER
INPUT?
INVALID
OUTPUT
NO
H
H
Active
Active
Active
NO
L
NO
H
H
Active
Active
Active
YES
H
YES
H
L
Active
Active
Active
NO
L
YES
H
L
Active
Active
Active
YES
H
NO
H
L
High-Z
Active
Active
NO
L
NO
H
L
High-Z
Active
Active
YES
H
X
L
X
High-Z
High-Z
Active
NO
L
X
L
X
High-Z
High-Z
Active
YES
H
MODE OF OPERATION
Normal Operation (Enhanced
Auto Powerdown Disabled)
Normal Operation (Enhanced
Auto Powerdown Enabled)
Powerdown Due to Enhanced
Auto Powerdown Logic
Manual Powerdown
INVALID DRIVING FORCEON AND FORCEOFF (EMULATES AUTOMATIC POWERDOWN)
X
NOTE 8
NOTE 8
Active
Active
Active
YES
H
Normal Operation
X
NOTE 8
NOTE 8
High-Z
High-Z
Active
NO
L
Forced Auto Powerdown
NOTE:
8. Input is connected to INVALID Output.
Transmitter inputs on the ISL424XE float if left unconnected,
and may cause ICC increases. Connect unused inputs to
GND for the best performance. ISL4238E transmitter inputs
incorporate an active positive feedback resistor that
maintains the last input state in the absence of a forcing
signal, so unused transmitter inputs may be left
unconnected.
prevent current flow through the peripheral’s protection
diodes (see Figures 2 and 3). This renders them useless for
wake up functions, but the corresponding monitor receiver
can be dedicated to this task as shown in Figure 3.
VCC
VCC
CURRENT
FLOW
VCC
Receivers
ISL4238E/4XE devices contain standard inverting receivers
which can tristate via the FORCEOFF control line.
Additionally, they include a noninverting (monitor) receiver
(denoted by the ROUTB label) that is always active,
regardless of the state of any control lines. Both receiver
types convert RS-232 signals to CMOS output levels and
accept inputs up to ±25V while presenting the required 3kΩ
to 7kΩ input impedance (see Figure 1) even if the power is
off (VCC = 0V). The receivers’ Schmitt trigger input stage
uses hysteresis to increase noise immunity and decrease
errors due to slow input signal transitions.
VOUT = VCC
Rx
POWERED
DOWN
UART
Tx
GND
SHDN = GND
OLD
RS-232 CHIP
FIGURE 2. POWER DRAIN THROUGH POWERED DOWN
PERIPHERAL
VCC
RXIN
-25V ≤ VRIN ≤ +25V
RXOUT
GND ≤ VROUT ≤ VCC
5kΩ
GND
FIGURE 1. INVERTING RECEIVER CONNECTIONS
The ISL4238E/4XE inverting receivers disable during forced
(manual) powerdown, but not during automatic powerdown
(see Table 2). Conversely, the monitor receiver remains
active even during manual powerdown making it extremely
useful for Ring Indicator monitoring. Standard receivers
driving powered down peripherals must be disabled to
9
Low Power Operation
These 3V devices require a nominal supply current of
0.3mA, even at VCC = 5.5V, during normal operation (not in
powerdown mode). This is considerably less than the 5mA to
11mA current required by comparable 5V RS-232 devices,
allowing users to reduce system power simply by switching
to this new family.
ISL4238E, ISL4244E, ISL4245E
VCC
FORCEOFF
PWR
MGT
LOGIC
TRANSITION
DETECTOR
TO
WAKE-UP
LOGIC
FORCEON
INVALID
ISL4238E/4XE
ISL4238E/4XE
VCC
ROUTB
RX
POWERED
DOWN
UART
ROUT
TX
I/O
UART
VOUT = HI-Z
RIN
CPU
T1IN
T1OUT
FORCEOFF = GND
FIGURE 3. DISABLED RECEIVERS PREVENT POWER DRAIN
Powerdown Functionality
The already low current requirement drops significantly
when the device enters powerdown mode. In powerdown,
supply current drops to 10nA, because the on-chip charge
pump turns off (V+ collapses to VCC, V- collapses to GND),
and the transmitter outputs tristate. Inverting receiver
outputs disable only in manual powerdown; refer to Table 2
for details. This micro-power mode makes these devices
ideal for battery powered and portable applications.
Software Controlled (Manual) Powerdown
These devices allow the user to force the IC into the low
power, standby state, and utilize a two pin approach where
the FORCEON and FORCEOFF inputs determine the IC’s
mode. For always enabled operation, FORCEON and
FORCEOFF are both strapped high. To switch between
active and powerdown modes, under logic or software
control, only the FORCEOFF input need be driven. The
FORCEON state isn’t critical, as FORCEOFF dominates
over FORCEON. Nevertheless, if strictly manual control over
powerdown is desired, the user must strap FORCEON high
to disable the enhanced automatic powerdown circuitry.
ISL4238E/4XE inverting (standard) receiver outputs also
disable when the device is in manual powerdown, thereby
eliminating the possible current path through a shutdown
peripheral’s input protection diode (see Figures 2 and 3).
Connecting FORCEOFF and FORCEON together disables
the enhanced automatic powerdown feature, enabling them
to function as a manual SHUTDOWN input (see Figure 4).
With any of the above control schemes, the time required to
exit powerdown, and resume transmission is only 100µs.
10
FIGURE 4. CONNECTIONS FOR MANUAL POWERDOWN
WHEN NO VALID RECEIVER SIGNALS ARE
PRESENT
When using both manual and enhanced automatic
powerdown (FORCEON = 0), the ISL4238E/4XE won’t
power up from manual powerdown until both FORCEOFF
and FORCEON are driven high, or until a transition occurs
on a receiver or transmitter input. Figure 5 illustrates a circuit
for ensuring that the ISL4238E/4XE powers up as soon as
FORCEOFF switches high. The rising edge of the Master
Powerdown signal forces the device to power up, and the
ISL4238E/4XE returns to enhanced automatic powerdown
mode an RC time constant after this rising edge. The time
constant isn’t critical, because the ISL4238E/4XE remains
powered up for 30 seconds after the FORCEON falling edge,
even if there are no signal transitions. This gives slow-towake systems (e.g., a mouse) plenty of time to start
transmitting, and as long as it starts transmitting within 30
seconds both systems remain enabled.
POWER
MANAGEMENT
UNIT
MASTER POWERDOWN LINE
0.1µF
FORCEOFF
1MΩ
FORCEON
ISL4238E/4XE
FIGURE 5. CIRCUIT TO ENSURE IMMEDIATE POWER UP
WHEN EXITING FORCED POWERDOWN
INVALID Output
The INVALID output always indicates (see Table 2) whether
or not 30µs have elapsed with invalid RS-232 signals (see
Figures 6 and 9) persisting on all of the receiver inputs,
giving the user an easy way to determine when the interface
block should power down. Invalid receiver levels occur
whenever the driving peripheral’s outputs are shut off
(powered down) or when the RS-232 interface cable is
disconnected. In the case of a disconnected interface cable
where all the receiver inputs are floating (but pulled to GND
ISL4238E, ISL4244E, ISL4245E
by the internal receiver pull down resistors), the INVALID
logic detects the invalid levels and drives the output low. The
power management logic then uses this indicator to power
down the interface block. Reconnecting the cable restores
valid levels at the receiver inputs, INVALID switches high,
and the power management logic wakes up the interface
block. INVALID can also be used to indicate the DTR or
RING INDICATOR signal, as long as the other receiver
inputs are floating, or driven to GND (as in the case of a
powered down driver).
INVALID switches high 1µs after detecting a valid RS-232
level on a receiver input. INVALID operates in all modes
(forced or automatic powerdown, or forced on), so it is also
useful for systems employing manual powerdown circuitry.
FORCEOFF
T_IN
EDGE
DETECT
S
30sec
TIMER
R_IN
EDGE
DETECT
AUTOPWDN
R
FORCEON
FIGURE 7. ENHANCED AUTOMATIC POWERDOWN LOGIC
on the state of the ISL4238E/4XE (see the next sections for
methods of utilizing INVALID to power down the device).
The time to recover from automatic powerdown mode is
typically 100µs.
VALID RS-232 LEVEL - INVALID = 1
2.7V
Emulating Standard Automatic Powerdown
INDETERMINATE
0.3V
INVALID LEVEL - INVALID = 0
-0.3V
INDETERMINATE
-2.7V
VALID RS-232 LEVEL - INVALID = 1
FIGURE 6. DEFINITION OF VALID RS-232 RECEIVER LEVELS
Enhanced Automatic Powerdown
Even greater power savings is available by using these devices
which feature an enhanced automatic powerdown function.
When the enhanced powerdown logic determines that no
transitions have occurred on any of the transmitter nor receiver
inputs for 30 seconds, the charge pump and transmitters
powerdown, thereby reducing supply current to 10nA. The
ISL4238E/4XE automatically powers back up whenever it
detects a transition on one of these inputs. This automatic
powerdown feature provides additional system power savings
without changes to the existing operating system.
Enhanced automatic powerdown operates when the
FORCEON input is low, and the FORCEOFF input is high.
Tying FORCEON high disables automatic powerdown, but
manual powerdown is always available via the overriding
FORCEOFF input. Table 2 summarizes the enhanced
automatic powerdown functionality.
If enhanced automatic powerdown isn’t desired, the user can
implement the standard automatic powerdown feature (mimics
the function on the ISL4243E) by connecting the INVALID
output to the FORCEON and FORCEOFF inputs, as shown in
Figure 8. After 30µs of invalid receiver levels, INVALID switches
low and drives the ISL4238E/4XE into a forced powerdown
condition. INVALID switches high as soon as a receiver input
senses a valid RS-232 level, forcing the ISL4238E/4XE to
power on. See the “INVALID DRIVING FORCEON AND
FORCEOFF” section of Table 2 for an operational summary.
This operational mode is perfect for handheld devices that
communicate with another computer via a detachable cable.
Detaching the cable allows the internal receiver pull-down
resistors to pull the inputs to GND (an invalid RS-232 level),
causing the 30µs timer to time-out and drive the IC into
powerdown. Reconnecting the cable restores valid levels,
causing the IC to power back up.
FORCEON
INVALID
FORCEOFF
ISL4238E/4XE
I/O
UART
CPU
Figure 7 illustrates the enhanced powerdown control logic.
Note that once the ISL4238E/4XE enters powerdown
(manually or automatically), the 30 second timer remains
timed out (set), keeping the ISL4238E/4XE powered down
until FORCEON transitions high, or until a transition occurs
on a receiver or transmitter input.
Hybrid Automatic Powerdown Options
The INVALID output signal switches low to indicate that
invalid levels have persisted on all of the receiver inputs for
more than 30µs (see Figure 9), but this has no direct effect
For devices which communicate only through a detachable
cable, connecting INVALID to FORCEOFF (with
FORCEON = 0) may be a desirable configuration. While the
11
FIGURE 8. CONNECTIONS FOR AUTOMATIC POWERDOWN
WHEN NO VALID RECEIVER SIGNALS ARE
PRESENT
ISL4238E, ISL4244E, ISL4245E
RECEIVER
INPUTS
INVALID
} REGION
TRANSMITTER
INPUTS
TRANSMITTER
OUTPUTS
tINVH
INVALID
OUTPUT
tINVL
tAUTOPWDN
tAUTOPWDN
tWU
tWU
OUTPUT
V+
VCC
0
V-
FIGURE 9. ENHANCED AUTOMATIC POWERDOWN AND INVALID TIMING DIAGRAMS
cable is attached INVALID and FORCEOFF remain high, so
the enhanced automatic powerdown logic powers down the
RS-232 device whenever there is 30 seconds of inactivity on
the receiver and transmitter inputs. Detaching the cable
allows the receiver inputs to drop to an invalid level (GND),
so INVALID switches low and forces the RS-232 device to
power down. The ISL4238E/4XE remains powered down
until the cable is reconnected (INVALID = FORCEOFF = 1)
and a transition occurs on a receiver or transmitter input (see
Figure 7). For immediate power up when the cable is
reattached, connect FORCEON to FORCEOFF through a
network similar to that shown in Figure 5.
Capacitor Selection
The ISL4238E charge pumps require 0.1µF, or greater,
capacitors for 3.3V (5% tolerance) operation. For other
supply voltages refer to Table 3 for capacitor values. Do not
use values smaller than those listed in Table 3.
TABLE 3. REQUIRED CAPACITOR VALUES (ISL4238E)
When using minimum required capacitor values, make sure
that capacitor values do not degrade excessively with
temperature. If in doubt, use capacitors with a larger nominal
value. The capacitor’s equivalent series resistance (ESR)
usually rises at low temperatures and it influences the
amount of ripple on V+ and V-.
Power Supply Decoupling
In most circumstances a 0.1µF bypass capacitor is
adequate. In applications that are particularly sensitive to
power supply noise, decouple VCC to ground with a
capacitor of the same value as the charge-pump capacitor C1.
Connect the bypass capacitor as close as possible to the IC.
Transmitter Outputs when Exiting
Powerdown
Figure 10 shows the response of two transmitter outputs
when exiting powerdown mode. As they activate, the two
transmitter outputs properly go to opposite RS-232 levels,
with no glitching, ringing, nor undesirable transients. Each
transmitter is loaded with 3kΩ in parallel with 2500pF. Note
that the transmitters enable only when the magnitude of the
supplies exceed approximately 3V.
VCC (V)
C1 (µF)
C2, C3, C4 (µF)
3.0 to 3.6 (3.3V ±10%)
0.22
0.22
3.15 to 3.6 (3.3V ±5%)
0.1
0.1
Operation Down to 2.7V
4.5 to 5.5
0.047
0.33
3.0 to 5.5
0.22
1
ISL4238E/4XE transmitter outputs meet RS-562 levels
(±3.7V), at the full data rate, with VCC as low as 2.7V.
RS-562 levels typically ensure interoperability with RS-232
devices.
The ISL4244E/45E charge pumps require 0.1µF capacitors
for proper operation. Increasing the capacitor values (by a
factor of 2) reduces ripple on the transmitter outputs and
slightly reduces power consumption. C2, C3, and C4 can be
increased without increasing C1’s value, however, do not
increase C1 without also increasing C2, C3, and C4 to
maintain the proper ratios (C1 to the other capacitors).
12
ISL4238E, ISL4244E, ISL4245E
5V/DIV
for a single transmitter driving 250pF and an RS-232 load at
1Mbps. The static transmitters were also loaded with an
RS-232 receiver.
FORCEOFF
T1
VCC
+
0.1µF
2V/DIV
+
VCC
C1+
V+
C1
C1ISL4238E/4XE
T2
+
V-
C2+
C2
VCC = +3.3V
C1 - C4 = 0.1µF
C4
+
C2TIN
TIME (20µs/DIV.)
FIGURE 10. TRANSMITTER OUTPUTS WHEN EXITING
POWERDOWN
TOUT
RIN
ROUT
Mouse Driveability
FORCEON
The ISL424XE are specifically designed to power a serial
mouse while operating from low voltage supplies. Figure 11
shows the transmitter output voltages under increasing load
current. The on-chip switching regulator ensures the
transmitters will supply at least ±5V during worst case
conditions (15mA for paralleled V+ transmitters, 7.3mA for
single V- transmitter).
VCC
CL
5k
FORCEOFF
FIGURE 12. TRANSMITTER LOOPBACK TEST CIRCUIT
5V/DIV.
6
TRANSMITTER OUTPUT VOLTAGE (V)
+
C3
T1IN
5
VOUT+
4
VCC = 3.0V
3
2
T1OUT
T1
1
VOUT+
0
T2
-1
ISL424XE
-2
VCC
-3
R1OUT
VOUT -
T3
VCC = +3.3V
C1 - C4 = 0.1µF
VOUT -
-4
-5
5µs/DIV.
-6
0
1
2
3
4
5
6
7
8
9
10
FIGURE 13. ISL4238E/44E LOOPBACK TEST AT 120kbps
LOAD CURRENT PER TRANSMITTER (mA)
FIGURE 11. TRANSMITTER OUTPUT VOLTAGE vs LOAD
CURRENT (PER TRANSMITTER, i.e., DOUBLE
CURRENT AXIS FOR TOTAL VOUT+ CURRENT)
5V/DIV.
T1IN
High Data Rates
The ISL4238E/4XE maintain the RS-232 ±5V minimum
transmitter output voltages even at high data rates. Figure 12
details a transmitter loopback test circuit, and Figure 13
illustrates the ISL4238E/44E loopback test result at
120kbps. For this test, all transmitters were simultaneously
driving RS-232 loads in parallel with 1000pF, at 120kbps.
Figure 14 shows the ISL4238E/44E loopback results for a
single transmitter driving 1000pF and an RS-232 load at
250kbps. Figure 15 illustrates the ISL4245E loopback test
result at 250kbps. For this test, all transmitters were
simultaneously driving RS-232 loads in parallel with 1000pF,
at 250kbps. Figure 16 shows the ISL4245E loopback results
13
T1OUT
R1OUT
VCC = +3.3V
C1 - C4 = 0.1µF
2µs/DIV.
FIGURE 14. ISL4238E/44E LOOPBACK TEST AT 250kbps
(CL = 1000pF)
ISL4238E, ISL4244E, ISL4245E
TABLE 4. LOGIC FAMILY COMPATIBILITY WITH VARIOUS
SUPPLY VOLTAGES
5V/DIV.
VCC
SYSTEM
POWER-SUPPLY SUPPLY
VOLTAGE
VOLTAGE
(V)
(V)
T1IN
T1OUT
R1OUT
3.3
3.3
5
5
5
3.3
VCC = +3.3V
C1 - C4 = 0.1µF
2µs/DIV.
COMPATIBILITY
Compatible with all CMOS
families.
Compatible with all TTL and
CMOS logic families.
Compatible with ACT and HCT
CMOS, and with TTL.
ISL4238E/4XE outputs are
incompatible with AC, HC, and
CD4000 CMOS inputs.
FIGURE 15. ISL4245E LOOPBACK TEST AT 250kbps
±15kV ESD Protection
All pins on ISL4238E/4XE devices include ESD protection
structures, but the RS-232 pins (transmitter outputs and
receiver inputs) incorporate advanced structures which allow
them to survive ESD events up to ±15kV. The RS-232 pins
are particularly vulnerable to ESD damage because they
typically connect to an exposed port on the exterior of the
finished product. Simply touching the port pins, or
connecting a cable, can cause an ESD event that might
destroy unprotected ICs. These new ESD structures protect
the device whether or not it is powered up, protect without
allowing any latchup mechanism to activate, and don’t
interfere with RS-232 signals as large as ±25V.
5V/DIV.
T1IN
T1OUT
R1OUT
VCC = +3.3V
C1 - C4 = 0.1µF
0.5µs/DIV.
FIGURE 16. ISL4245E LOOPBACK TEST AT 1Mbps
(CL = 250pF)
Interconnection with 3V and 5V Logic
The ISL4238E/4XE directly interface with 5V CMOS and TTL
logic families. Nevertheless, with the ISL4238E/4XE at 3.3V,
and the logic supply at 5V, AC, HC, and CD4000 outputs can
drive ISL4238E/4XE inputs, but ISL4238E/4XE outputs do
not reach the minimum VIH for these logic families. See
Table 4 for more information.
Human Body Model (HBM) Testing
As the name implies, this test method emulates the ESD
event delivered to an IC during human handling. The tester
delivers the charge through a 1.5kΩ current limiting resistor,
making the test less severe than the IEC6100 test which
utilizes a 330Ω limiting resistor. The HBM method
determines an ICs ability to withstand the ESD transients
typically present during handling and manufacturing. Due to
the random nature of these events, each pin is tested with
respect to all other pins. The RS-232 pins on “E” family
devices can withstand HBM ESD events to ±15kV.
IEC6100-4-2 Testing
The IEC6100 test method applies to finished equipment,
rather than to an individual IC. Therefore, the pins most likely
to suffer an ESD event are those that are exposed to the
outside world (the RS-232 pins in this case), and the IC is
tested in its typical application configuration (power applied)
rather than testing each pin-to-pin combination. The lower
current limiting resistor coupled with the larger charge
storage capacitor yields a test that is much more severe than
the HBM test. The extra ESD protection built into this
device’s RS-232 pins allows the design of equipment
meeting level 4 criteria without the need for additional board
level protection on the RS-232 port.
14
ISL4238E, ISL4244E, ISL4245E
AIR-GAP DISCHARGE TEST METHOD
CONTACT DISCHARGE TEST METHOD
For this test method, a charged probe tip moves toward the
IC pin until the voltage arcs to it. The current waveform
delivered to the IC pin depends on approach speed,
humidity, temperature, etc., so it is difficult to obtain
repeatable results. The “E” device RS-232 pins withstand
±15kV air-gap discharges.
During the contact discharge test, the probe contacts the
tested pin before the probe tip is energized, thereby
eliminating the variables associated with the air-gap
discharge. The result is a more repeatable and predictable
test, but equipment limits prevent testing devices at voltages
higher than ±8kV. All “E” family devices survive ±8kV contact
discharges on the RS-232 pins.
Typical Performance Curves
VCC = 3.3V, TA = 25oC
6
TRANSMITTER OUTPUT VOLTAGE (V)
TRANSMITTER OUTPUT VOLTAGE (V)
6
VOUT+
4
2
1 TRANSMITTER AT 250kbps
OTHER TRANSMITTERS AT 30kbps
0
-2
VOUT -
-4
-6
VOUT+
4
2
1 TRANSMITTER AT 250kbps
OTHER TRANSMITTERS AT 30kbps
0
-2
-4
VOUT -
-6
0
1000
2000
3000
4000
0
5000
1000
3000
4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
FIGURE 17. ISL4238E TRANSMITTER OUTPUT VOLTAGE vs
LOAD CAPACITANCE
FIGURE 18. ISL4244E TRANSMITTER OUTPUT VOLTAGE vs
LOAD CAPACITANCE
6
55
VOUT+
1 TRANSMITTER AT INDICATED RATE
50
4
SUPPLY CURRENT (mA)
TRANSMITTER OUTPUT VOLTAGE (V)
2000
2
1 TRANSMITTER AT 1Mbps
OTHER TRANSMITTERS AT 30kbps
0
-2
VOUT -
-4
45
250kbps
40
120kbps
35
30
25
-6
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
FIGURE 19. ISL4245E TRANSMITTER OUTPUT VOLTAGE vs
LOAD CAPACITANCE
15
20kbps
20
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
FIGURE 20. ISL4238E SUPPLY CURRENT vs LOAD
CAPACITANCE WHEN TRANSMITTING DATA
ISL4238E, ISL4244E, ISL4245E
Typical Performance Curves
VCC = 3.3V, TA = 25oC (Continued)
90
1 TRANSMITTER AT INDICATED RATE
45
80
1 TRANSMITTER AT INDICATED RATE
1Mbps
250kbps
70
35
SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
40
30
120kbps
25
20
20kbps
15
60
50
250kbps
40
30
120kbps
20
10
0
2000
1000
4000
3000
5000
10
0
LOAD CAPACITANCE (pF)
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
FIGURE 21. ISL4244E SUPPLY CURRENT vs LOAD
CAPACITANCE WHEN TRANSMITTING DATA
FIGURE 22. ISL4245E SUPPLY CURRENT vs LOAD
CAPACITANCE WHEN TRANSMITTING DATA
25
110
90
+SLEW
-SLEW
SLEW RATE (V/µs)
SLEW RATE (V/µs)
20
15
+SLEW
10
70
50
-SLEW
30
10
5
0
0
1000
2000
3000
4000
5000
0
1000
LOAD CAPACITANCE (pF)
Die Characteristics
NO LOAD
ALL OUTPUTS STATIC
3.0
SUBSTRATE POTENTIAL (POWERED UP)
GND
TRANSISTOR COUNT
2.5
ISL4238E: 1235
ISL4244E: 1109
ISL4245E: 1109
2.0
1.5
PROCESS
1.0
Si Gate CMOS
0.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
FIGURE 25. SUPPLY CURRENT vs SUPPLY VOLTAGE
16
4000
5000
FIGURE 24. ISL4245E SLEW RATE vs LOAD CAPACITANCE
3.5
SUPPLY CURRENT (mA)
3000
LOAD CAPACITANCE (pF)
FIGURE 23. ISL4238E/44E SLEW RATE vs LOAD
CAPACITANCE
0
2.5
2000
6.0
ISL4238E, ISL4244E, ISL4245E
Quad Flat No-Lead Plastic Package (QFN)
Micro Lead Frame Plastic Package (MLFP)
L32.5x5
32 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE
(COMPLIANT TO JEDEC MO-220VHHD-2 ISSUE C
MILLIMETERS
SYMBOL
MIN
NOMINAL
MAX
NOTES
A
0.80
0.90
1.00
-
A1
-
-
0.05
-
A2
-
-
1.00
9
A3
b
0.20 REF
0.18
D
0.30
5,8
5.00 BSC
D1
D2
0.23
9
-
4.75 BSC
2.95
3.10
9
3.25
7,8
E
5.00 BSC
-
E1
4.75 BSC
9
E2
2.95
e
3.10
3.25
7,8
0.50 BSC
-
k
0.25
-
-
-
L
0.30
0.40
0.50
8
L1
-
-
0.15
10
N
Nd
32
2
8
3
Ne
8
8
3
P
-
-
0.60
9
θ
-
-
12
9
Rev. 1 10/02
NOTES:
1. Dimensioning and tolerancing conform to ASME Y14.5-1994.
2. N is the number of terminals.
3. Nd and Ne refer to the number of terminals on each D and E.
4. All dimensions are in millimeters. Angles are in degrees.
5. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
7. Dimensions D2 and E2 are for the exposed pads which provide
improved electrical and thermal performance.
8. Nominal dimensions are provided to assist with PCB Land Pattern
Design efforts, see Intersil Technical Brief TB389.
9. Features and dimensions A2, A3, D1, E1, P & θ are present when
Anvil singulation method is used and not present for saw
singulation.
10. Depending on the method of lead termination at the edge of the
package, a maximum 0.15mm pull back (L1) maybe present. L
minus L1 to be equal to or greater than 0.3mm.
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