austriamicrosystems AG is now ams AG
The technical content of this austriamicrosystems datasheet is still valid.
Contact information:
Headquarters:
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten, Austria
Please visit our website at
www.ams.com
D a t a s h e e t
A S 1 7 2 0
S o l e n o i d / Va l v e D r i v e r w i t h C u r r e n t L i m i t a t i o n
1 General Description 2 Key Features
The AS1720A is a low side current source providing an optimized
DC Operation for power saving and ultra low electromagnetic radiation.
Supply Range: +5V to +50V
Internal VDDA: 3.3V
The AS1720A and AS1720B can be set to provide a strong initial closure current and is automatically switching to hold mode for power saving. The initial DC current, the hold current and the duty cycle of the PWM can be adjusted by external resistors. An internal thermal sensor prevents damage of the circuit due to excessive heating up.
1
VDDHV
Supply Current: 1 mA
The AS1720B is a low side switch providing a PWM output, which frequency is defined by an internal RC oscillator. The adjustable
PWM allows a fine control of the power delivered to the load.
Table 1. Standard Products
Model
AS1720A
AS1720B
Operation Mode
DC Current Source Operation
PWM Switching Operation
Both devices are optimized for driving electromechanical devices such as valves, solenoids relays, actuators and positioners.
Figure 1. AS1720 - Block Diagram
Vsupply: +5V to +50V
100nF
Internal osc frequency: 30kHz
Fix delay: 136ms
Adjustable duty cycle: 20% – 90% (AS1720B only)
Adjustable energizing current: 10mA – 100mA
Adjustable hold current: 30% - 70% of energizing current
valid
Current Limitation
Thermal shutdown: 150ºC
8-pin MLPD (2x2mm) Package
On request SOIC 8 Package (reduced temperature range -40°C
AG still
The AS1720 is ideal for fluid and gas flow systems, industrial control, electrical heaters, motor speed control.
ams
Internal VDDA typ. 3.3V
LDO &
Ref Generator
AS1720
2
VDDA
30kHz
Oscillator
Delay
L
Free-
Wheeling
Diode
R1
3 adjustable
Duty cycle
V ref
PWM &
R2
DUTY
VDDA
R
PU
8
Control
Technical
ENN
IE 6
Thermal
Shutdown
Current
Adjust
IH 7
4
OUT
5
VSS
R
L
10nF
Off
On
R
IE
R
IH
Energising Current adjust www.austriamicrosystems.com/Solenoid-Relay-Driver/AS1720
Hold Current adjust
Revision 1.04
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AS1720
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
Figure 2. Pin Out (Top View)
Pin Description
Table 2. Pin Descriptions
Pin Name
VDDHV
VDDA
Pin Number
1
2
DUTY
OUT
VSS
IE
IH
ENN
3
6
7
4
5
8
8 ENN VDDHV
1
VDDA 2 7 IH
AS1720
DUTY 3 6 IE
OUT 4 5 VSS
valid
Positive supply voltage
Internal supply of 3.3V (typ.)
Duty-Cycle.
Description
AG
pin to V
DDA
the 50% duty cycle is selected automatically.
Current Source Output still
phase. The duty cycle can be adjusted by a voltage source or an external resistor divider. Setting this
Ground
Energize Current.
This pin defines the current during energize phase by means of a resistor.
ams
the hold phase.
Low: The device starts with the energise phase, followed by the hold phase.
Technical
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AS1720
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 3
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
Section 6 Electrical Characteristics on page 4 is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Table 3. Absolute Maximum Ratings
Parameter
Electrical Parameters
VDDHV, OUT
VDDA, DUTY, ENN, IE, IH
Input Current (latch-up immunity)
Electrostatic Discharge
Electrostatic Discharge HBM
Temperature Ranges and Storage Conditions
Thermal Resistance
θ
JA
Junction Temperature T
J
Storage Temperature Range
Package Body Temperature
Humidity
Moisture Sensitive Level
Min
-0.9
-0.3
-100
-55
Max Units Notes
+55 V
+36
+140
+260
+/- 1.5
+5
100
V mA kV
Norm: JEDEC 78 @85°C
Norm: MIL 883 E method 3015
valid
ºC/W
+150
ºC
ºC
AG still
temperature) specified is in accordance with
IPC/
JEDEC J-STD-020 “Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State
Surface Mount Devices”.
The lead finish for Pb-free leaded packages is matte tin (100% Sn).
% Non-condensing
Represents a max. floor life time of unlimited
content
Technical
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AS1720
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
DDHV
= 5V, V
SS
= 0V, Typical Values are at T
AMB
= +25ºC (unless otherwise specified). All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods.
Table 4. Electrical Characteristics
Symbol
T
AMB
Parameter
Operating Ambient Temperature
T
J
Operating Junction Temperature
valid for AS1720A & AS1720B
V
DDHV
V
DDA
I
DD
Supply Voltage Range
Internal Supply
Supply Current
I
OUT_E
Output Energizing Current Range
1 defined by R
IE
(see Figure 10 on page 7)
V
IH
T
SHDN
Digital Input Threshold
Delay Time
Thermal Shutdown Temperature
@ pin ENN
V
IL
V
HYST
R
PU
Hysteresis
Pull-Up Resistor
@ pin ENN
@ pin ENN
AG
∆
T
SHDN
Thermal Shutdown Hysteresis
only valid for AS1720A
V
OUT k Transfer Value
Output Hold Current Range
1
ams
= 100mA
R
IE
= 12k
Ω
, V
DDHV
= 5V to 50V, OUT =
1V to 40V (see page 7)
defined by R
IH
(see Figure 10 on page 7)
1080
0.3 x
I
OUT_E
I
OUT_H
Saturation Voltage, Sink
1
V
SS
2
only valid for AS1720B
10
V trig
Minimum Duty Cycle
Maximum Duty Cycle
Internal Duty Cycle
Trigger level to select internal voltage divider
PWM Frequency
Conditions
no load
@ pin DUTY
15
83 f
PWM
Min
-40
-40
5
3.1
25.5
Typ
3.3
1
200
100
136
160
15
0.6
1200
20
90
50
V
DDA
30
Max
+85
+125
50
3.5
2
100
1
1320
0.7 x
I
OUT_E
25
95
34.5
Units
°C
°C
V mV k
Ω ms
ºC
ºC
V
A
Ω mA
%
%
%
V kHz
V
V mA mA
valid
1. The parameters are tested with proprietary test modes.
Technical
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AS1720
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
V
SUPPLY
= 5V, R
IE
= 30k
Ω
, R
IH
= 120k
Ω
, T
AMB
= +25ºC (unless otherwise specified);
Figure 3. Duty Cycle vs. V
DUTY
90
Figure 4. PWM Frequency vs. Temperature
35
80
34
33
70
32
31
60
50
40
30
29
28
27
30
26
20
440
430
420
410
400
390
380
370
360
0.5
0.75
1 1.25
1.5
1.75
2 2.25
2.5
Voltage @ pin DUTY (V)
Figure 5. Supply Current vs. Supply Voltage
25
-40 -20 0 20 40 60 80 100 120
AG
500
Temperature (°C)
ams
450
400
content
300
5 10 15 20 25 30 35 40 45 50
V
DDHV
(V)
-40 -20 0 20 40 60 80 100 120
Temperature (°C)
valid
Figure 7. Transfer Function vs. Supply Voltage
1400
Figure 8. Transfer Function vs. Temperature
1400
1350 1350
1300 1300
1250
1200
1150
1100
Technical
1250
1200
1150
1100
1050
5 10 15 20 25
V
DDHV
(V)
30 35 www.austriamicrosystems.com/Solenoid-Relay-Driver/AS1720
40
1050
Revision 1.04
-40 -20 0 20 40 60 80 100 120
Temperature (°C)
5 - 12
AS1720
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
Delay
The delay time is generated internally by a digital divider.
LDO and Reference Generator
This block provides the internal supply voltage of typ. 3.3V and all bias currents for the analog cells. Further the external resistor divider for setting the duty cycle will be supplied.
Thermal shutdown
The temperature is constantly monitored. If the temperature exceeds typ. 160ºC the output is disabled. In order to exit the over temperature condition the system restarts beginning with the energizing phase followed by the hold phase.
DC Operation (AS1720A only)
valid
After power up, the delay time
(see Delay)
starts running. After expiration of the delay the hold phase starts automatically. During the hold phase the DC output current is reduced according to the R
IH
on pin IH.
PWM Operation (AS1720B only)
After power up, the delay time
(see Delay)
still
driven by a voltage source. For using the internal divider the pin DUTY has to be connected to V
DDA
. The comparator recognizes this condition and switches to the internal divider, which causes a fixed 50% duty cycle.
AG
DUTY
)
= 0 381
×
V
DUTY
–
(EQ 1)
VDDA
content
30kHz
Oscillator
Delay adjustable
Duty cycle
R1
DUTY
R2
V ref
PWM &
Control fixed
50% Duty cycle optional
VDDA
VDDA
R
PU
ENN
Off
On www.austriamicrosystems.com/Solenoid-Relay-Driver/AS1720 Revision 1.04
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AS1720
Datasheet - D e t a i l e d D e s c r i p t i o n
Control by pin ENN
When VDDHV is constantly switched on the AS1720 can be controlled by pin ENN. The functionality is the same as for controlling the device via pin VDDHV. This feature is useful when controlling by a microprocessor is desired.
Because of the internal pull-up resistor to V
DDA
a microprocessor with open-drain or with push/pull (max 3.3V) output can be used.
Current Adjust (AS1720A) and Current Limitation (AS1720B)
This block provides the current reference for the output current source. The current is generated by regulating the internal Bandgap voltage to the pins IE and IH. The external resistors R
IE
and R
IH
define the output current and can be expressed as:
R
=
I
OUT
(EQ 2)
The saturation voltage of the output current source for a 100mA current is typical 600mV.
Figure 10. Simplified Circuit of Blocks Current Adjust and Current Source
1.2V reference
1.2V
Current mirror
AG
PWM & Control
OUT
still
R
IE
IH
content
Technical
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AS1720
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9 Application Information
In order to drive relays, which need more than 100mA current, an external circuitry
(see Figure 11) can be used. This application shows how to
drive 5W @12V relays.
This circuit is only applicable for AS1720A.
For this example with R1 = 100
Ω
and R
S
= 2.5
Ω
the current Is is calculated as follows:
I
S
=
I
1
×
R
------
R
S
=
×
---------
2 5
= 400mA
Figure 11. AS1720A - Typical Application
Vsupply: +12V
VDDHV
100nF
VDDA
DUTY
AS1720A
10mA
I
1
R1
100
Ω
AG
LM741
-
+
VSS
1V
Relay
(EQ 3)
I
S
R
S
still
BC161
valid
Free-
Wheeling
Diode
ENN
IE
R
IE
120k
Ω
Energising Current adjust
240k
Ω
Hold Current adjust
Technical
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AS1720
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
10 Package Drawings and Markings
Figure 12. 8-pin MLPD (2x2mm) Marking
AG still valid
Technical
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AS1720
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
Figure 13. 8-pin MLPD (2x2mm) Package
AG still valid
Technical
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AS1720
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The device is available as the standard products shown in Table 5
.
Table 5. Ordering Information
Ordering Code Marking
AS1720A-ATDT
AS1720B-ATDT
A0
AW
Description
Solenoid / Valve Driver with Current Limitation and with
DC Current Source Operation
Solenoid / Valve Driver with Current Limitation and with
PWM Switching Operation
Delivery Form
Tape and Reel
Tape and Reel
Package
8-pin MLPD (2x2mm)
8-pin MLPD (2x2mm)
Note:
All products are RoHS compliant and austriamicrosystems green.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
Technical Support is found at http://www.austriamicrosystems.com/Technical-Support
For further information and requests, please contact us mailto:[email protected]
or find your local distributor at http://www.austriamicrosystems.com/distributor
AG still valid
Technical
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AS1720
Datasheet
Copyrights
Copyright © 1997-2011, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®.
All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range,
valid
manufacturing flow might show deviations from the standard production flow, such as test flow or test location.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services.
AG still
Contact Information
Headquarters austriamicrosystems AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 3136 525 01
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