General Description
Figure 1:
Added Value of Using AS3728
Benefits
•
Support for single or dual phase operation
AS3728
8A Power Stage
The AS3728 is a companion power stage, intended to be used with AS372x products.
It cannot be used without a DCDC controller. It contains the power FETs for 2 phases and is capable to handle output currents up of 4A per phase.
Ordering Information
and
Content Guide appear at end of
datasheet.
Key Benefits & Features
The benefits and features of AS3728, 8A Power Stage are listed below:
•
2 x 4A output stages are running on 1.3MHz
•
Over – temperature protection
•
Cost effective, small package
Features
•
2 phases with separate control input
•
Separate power low-side NMOS & high-side NMOS for
4A per phase
•
Separate coil current feedback per phase
•
Stand-alone zero-crossing operation
•
Integrated temperature monitoring
•
WL-CSP24 with 0.4mm pitch
Applications
The device is a high current dual-phase DCDC and ideal for:
•
Mobile phones
•
Tablets
•
Notebooks
ams Datasheet
[v1-03] 2015-Aug-31
Page 1
Document Feedback
AS3728 −
General Description
Block Diagram
The functional blocks of this device for reference are shown below:
Figure 2:
AS3728 Block Diagram
VSUP clk
PWM
Logic
PWM ov_curr ramp
Vov_current
Σ
Current sense error ota
VRef
RCSNS
FB
CTRL2
CTRL1
VSS
TEMP
CTRL1
5VSUP
Ngate
Isense
Logic
Ngate
Zcomp
HVSUP
BOOST1
LX 1
1uH
47uF
PVSS
AS3728 – Block Diagram:
This figure shows the block diagram of the DCDC controller inside the Main PMIC and the AS3728 Power Stage with all relevant system components.
Page 2
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Pin Assignment
Pin Assignment
Figure 3:
Pin Diagram - 24 Balls WL-CSP with 0.4mm Pitch
Pin A1 indicator
A1
BOOST
1
A2
HVSUP
B1
CTRL1
B2
HVSUP
C1
5VSUP
C2
HVSUP
D1
TEMP
D2
HVSUP
E1
CTRL2
E2
HVSUP
F1
BOOST
2
F2
HVSUP
A3
LX1
B3
LX1
C3
LX1
D3
LX2
E3
LX2
F3
LX2
A4
PVSS
B4
PVSS
C4
PVSS
D4
PVSS
E4
PVSS
F4
PVSS
Figure 4:
Pin Description
Pin Number
A1
B1
C1
D1
E1
F1
A2, B2, C2
D2, E2, F2
A3, B3, C3
D3, E3, F3
A4, B4, C4
D4, E4, F4
Pin Name
BOOST1
CTRL1
5VSUP
TEMP
CTRL2
BOOST2
HVSUP
HVSUP
LX1
LX2
PVSS
PVSS
Pin Type
AIO
AI
S
S
AI
AIO
S
AIO
AIO
AIO
Description
Supply pin for phase 1 high-side NMOS driver
Control IO for phase 1
5V supply pin
ON/OFF control and temperature feedback
Control IO for phase 2
Supply pin for phase 2 high-side NMOS driver
Phase 1 positive supply terminal
Phase 2 positive supply terminal
Phase 1 switching output to coil
Phase 2 switching output to coil
Phase 1 negative supply terminal
Phase 2 negative supply terminal
Pin Description:
Shows the pin number, type, name and description of every pin.
ams Datasheet
[v1-03] 2015-Aug-31
Page 3
Document Feedback
Absolute Maximum Ratings
AS3728 −
Absolute Maximum R atings
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only. Functional operation of the device at these or any other conditions beyond those indicated under
Electrical
Characteristics is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
Figure 5:
Absolute Maximum Ratings
Symbol
V
GND
V
GND
V
GND
V
GND
I
SCR
P
T
ESD
Parameter Min Max Units Comments
Electrical Parameters
Supply Voltage to Ground 14V pins
Supply Voltage to Ground 20V pins
Supply Voltage to Ground 5V pins
Supply Voltage to Ground 3V pins
-0.5
-0.5
-0.5
-0.5
16
22
7.0
5.0
V
V
V
V
Applicable for pins HVSUP,
LX1, LX2
Applicable for pins BOOST1,
BOOST2
Applicable for pins 5VSUP,
CTRL1, CTRL2
Applicable for pin TEMP
Voltage Difference between Ground
Terminals
-0.5
0.5
V
Input Current (latch-up immunity) -100 100 mA
Continuous Power Dissipation (T
A
= 70°C)
Applicable for pins PVSS
Norm: JEDEC JESD78
Continuous power dissipation 1.3
mW
P
T
(1)
for WL-CSP24 package
(
R
THJA
~ 42K/W
)
Electrostatic Discharge HBM
Electrostatic Discharge
±2 kV Norm: JEDEC JESD22-A114F
Page 4
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Absolute Maximum Ratings
Symbol
T
A
R
THJA
T
J
T
STRG
T
BODY
RH
NC
MSL
Parameter Min Max Units Comments
Temperature Ranges and Storage Conditions
-40 85 °C Operating Temperature
Junction to Ambient Thermal
Resistance
°C/W
R
THJA
~ 42K/W (typ)
Junction Temperature
Storage Temperature Range -55
125
125
°C
°C
Package Body Temperature 260 °C
Norm IPC/JEDEC J-STD-020
(2)
Relative Humidity (non-condensing) 5 85 %
Moisture Sensitivity Level 1
Represents an unlimited floor life time
Note(s) and/or Footnote(s):
1. Depending on actual PCB layout and PCB used
2. The reflow peak soldering temperature (body temperature) is specified according IPC/JEDEC J-STD-020 “Moisture/Reflow Sensitivity
Classification for Nonhermetic Solid State Surface Mount Devices”.
ams Datasheet
[v1-03] 2015-Aug-31
Page 5
Document Feedback
AS3728 −
Electrical Characteristics
Electrical Characteristics
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical
Quality Control) methods.
Figure 6:
Electrical Characteristics
Symbol
V
IN
Parameter
Input Voltage
I
LIMIT
Peak coil current limit
I
LOAD
Load current
Single phase
R
HS-NMOS
R
LS-NMOS f
SW
N-switch ON resistance
N-switch ON resistance
Switching frequency
I
I
Q_HVSUP
Q_5VSUP
I power_off
R discharge
Quiescent current into
HVSUP
Quiescent current into
5VSUP
Power-Off current into HVSUP or 5VSUP
Active discharge
(2)
(2)
Min
0
0
4.5
4.5
0
20
115
30
1.3
Typ
12
28
3
4
(1)
180
14
5.5
5.5
3.6
5.6
Max Units
V
V
V
V
A
A mΩ
Note
Pin HVSUP
Pin 5VSUP
Pin CTRLx
Pin TEMP
Single phase
Continuous load current
Peak load current
Single phase
40
3
2
60 mΩ
MHz
μA
μA
Single phase
Supplied by DCDC controller
TEMP pin high, CTRLx pin high
TEMP pin high, CTRLx pin high
1 μA No current into pin TEMP
Ω Single phase
Electrical Characteristics:
Shows the Electrical Characteristics of the Step Down DCDC Power Stage.
HVSUP = 5VSUP = 5.0V, T
A
= 25°C (unless otherwise specified)
Note(s) and/or Footnote(s):
1. Maximum value only for pulsed peak current
2. MOS transistor and package parasitic
Page 6
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Typical Operating Characteristics
Typical Operating
Characteristics
Figure 7:
Efficiency vs. Output Current
AS3728 Step Down DCDC
: Shows the
Efficiency vs. Output Current for various
V
IN
/V
OUT
conditions, 1.35MHz operation,
T
AMB
= 25°C
90
85
80
75
70
65
60
55
50
45
40
0.01
AS3728 5V-1.2V SPM4015 0.68uH 24.5m
Ω (1.35MHz)
AS3728 7.4V-1.1V SPM4015 0.68uH 24.5m
Ω (1.35MHz)
AS3728 12V-1.1V SPM4015 0.68uH 24.5m
Ω (1.35MHz)
AS3728 5V-1.2V SPM5030 0.75uH 8.5m
Ω combined (1.35MHz)
0.1
1
Output Current (A)
10
AS3728 Step Down DCDC
: Shows the
Efficiency vs. Output Current for various switching frequencies with V
OUT
= 1.2V,
V
IN
= 5V, T
AMB
= 25°C and TDK coil
SPM4015 and Coilcraft coil XFL4015
Figure 8:
Efficiency vs. Output Current
75
70
65
60
90
85
80
55
50
45
40
0.01
AS3728 5V-1.2V SPM4015 0.68uH 24.5m
Ω combined (1.35MHz)
AS3728 5V-1.2V SPM4015 0.68uH 24.5m
Ω combined (0.675MHz)
AS3728 5V-1.2V SPM4015 0.68uH 24.5m
Ω (1.35MHz)
AS3728 5V-1.2V XFL4015 0.47uH 7.6m
Ω combined (1.35MHz)
AS3728 5V-1.2V XFL4015 0.47uH 7.6m
Ω combined (0.675MHz)
0.1
1
Output Current (A)
10
ams Datasheet
[v1-03] 2015-Aug-31
Page 7
Document Feedback
AS3728 Step Down DCDC
: Shows the
Efficiency vs. Output Current for various switching frequencies with V
OUT
= 1.2V,
V
IN
= 5V, T
AMB
= 25°C and TDK coil
SPM5030
AS3728 −
Typical Operating Characteristics
Figure 9:
Efficiency vs. Output Current
90
85
80
75
70
65
60
55
50
45
40
0.01
AS3728 5V-1.2V SPM5030 0.35uH 3.9m
Ω combined (1.35MHz)
AS3728 5V-1.2V SPM5030 0.35uH 3.9m
Ω combined (0.675MHz)
AS3728 5V-1.2V SPM5030 0.35uH 3.9m
Ω combined (2.7MHz)
AS3728 5V-1.2V SPM5030 0.75uH 8.5m
Ω combined (1.35MHz)
AS3728 5V-1.2V SPM5030 0.75uH 8.5m
Ω combined (0.675MHz)
AS3728 5V-1.2V SPM5030 0.75uH 8.5m
Ω combined (2.7MHz)
0.1
1
Output Current (A)
10
AS3728 Step Down DCDC
: Shows the
Efficiency vs. Output Current for various coil types with a switching frequency of
1.35MHz, V
OUT
= 1.2V, V
IN
= 5V,
T
AMB
= 25°C
Figure 10:
Efficiency vs. Output Current
90
85
80
75
70
65
60
55
50
45
40
0.01
AS3728 5V-1.2V SPM5030 0.75uH 8.5m
Ω combined (1.35MHz)
AS3728 5V-1.2V XFL4015 0.47uH 7.6m
Ω combined (1.35MHz)
AS3728 5V-1.2V SPM4015 0.68uH 24.5m
Ω combined (1.35MHz)
AS3728 5V-1.2V SPM5030 0.35uH 3.9m
Ω combined (1.35MHz)
AS3728 5V-1.2V SPM4015 0.68uH 24.5m
Ω (1.35MHz)
0.1
1
Output Current (A)
10
Page 8
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Application Information
Application Information
Figure 11:
Typical Application Circuit
DCDC
0.6 – 1.5V
8A
1.3MHz
TEMP_SDx
CTRL1_SDx
CTRL2_SDx
FB_SDx
HVSUP
10uF
TEMP
CTRL1
CTRL2
5VSUP
1uF optional
HVSUP
10uF
BOOST1
LX 1
100nF
1uH
PVSS
PVSS
LX2
100nF
1uH
BOOST2
47uF
Vout (0.6-1.5V@8A)
DVM, 10mV steps
47uF
FB_SDx
Typical Application:
This figure shows the connection of the DCDC controller and the AS3728 Power Stage.
External Components
Figure 12:
Step Down DCDC Power Stage External Components
Symbol
C
FB
C
HVSUP
C
BOOST
C
5VSUP
L
Parameter
Output Capacitor
HV Input Capacitor
Boost Capacitor
5V Supply Capacitor
Inductor
Min Typ Max Units Note
External Components Per Phase
64 82 μF
Ceramic X5R or X7R / 6.3V high performance
32 47 μF
Ceramic X5R or X7R / 6.3V cost optimized
6 10 μF Ceramic X5R or X7R / 25V
0.5
100
1
1 nF
μF
μH
Ceramic X5R or X7R / 6.3V
Ceramic X5R or X7R / 6.3V
5A rated, 1MHz operation, low R
ON
External Components:
Shows the recommended values of the needed external components of the Step Down
DCDC Power Stage.
ams Datasheet
[v1-03] 2015-Aug-31
Page 9
Document Feedback
AS3728 −
Application Information
PCB Layout
Figure 13:
Layout Guidelines
L1
C
HVSUP1
CTRL1
C
5VSUP
TEMP
CTRL2
AS3728
XXXX
C
HVSUP2
Vout
L2
FB
AS3728 – Layout Guidelines:
This figure shows the recommended layout and placement of the external components for the 2-phase AS3728 Power Stage.
Page 10
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Package Drawings & Markings
Package Drawings & Markings
Figure 14:
24 Balls WL-CSP With 0.4mm Pitch & Marking
Note(s) and/or Footnote(s):
1. Pin1 = A1.
2. ccc Coplanarity.
3. All dimensions are in μm.
ams Datasheet
[v1-03] 2015-Aug-31
RoHS
Green
Page 11
Document Feedback
Figure 15:
AS3728 Marking
AS3728 −
Pack age Drawings & Mark ings
AS3728
XXXX
Figure 16:
AS3728 Package Code
XXXX
Tracecode
Page 12
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Ordering & Contact Information
Ordering & Contact Information
Figure 17:
Ordering Information
Ordering Code
AS3728-BWLT
AS3728-BWLM
Description
Power Stage for
Multi-Phase DCDC
Power Stage for
Multi-Phase DCDC
Package
24-pin WL-CSP
24-pin WL-CSP
Delivery Form Delivery Quantity
Tape & Reel
Mini T & R
12000 pcs/reel
500 pcs/reel
Buy our products or get free samples online at: www.ams.com/ICdirect
Technical Support is available at: www.ams.com/Technical-Support
Provide feedback about this document at: www.ams.com/Document-Feedback
For further information and requests, e-mail us at: [email protected]
For sales offices, distributors and representatives, please visit: www.ams.com/contact
Headquarters
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten
Austria, Europe
Tel: +43 (0) 3136 500 0
Website: www.ams.com
ams Datasheet
[v1-03] 2015-Aug-31
Page 13
Document Feedback
AS3728 −
RoHS Compliant & ams Green Statement
RoHS Compliant & ams Green
Statement
RoHS:
The term RoHS compliant means that ams AG products fully comply with current RoHS directives. Our semiconductor products do not contain any chemicals for all 6 substance categories, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, RoHS compliant products are suitable for use in specified lead-free processes.
ams Green (RoHS compliant and no Sb/Br):
ams Green defines that in addition to RoHS compliance, our products are free of Bromine (Br) and Antimony (Sb) based flame retardants
(Br or Sb do not exceed 0.1% by weight in homogeneous material).
Important Information:
The information provided in this statement represents ams AG knowledge and belief as of the date that it is provided. ams AG bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. ams AG has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ams AG and ams AG suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
Page 14
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Copyrights & Disclaimer
Copyrights & Disclaimer
Copyright ams AG, Tobelbader Strasse 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.
Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its General Terms of
Trade. ams AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by ams AG for each application. This product is provided by ams AG “AS IS” and any express or implied warranties, including, but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed.
ams 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 ams AG rendering of technical or other services.
ams Datasheet
[v1-03] 2015-Aug-31
Page 15
Document Feedback
AS3728 −
Document Status
Document Status
Document Status
Product Preview
Preliminary Datasheet
Datasheet
Datasheet (discontinued)
Product Status
Pre-Development
Pre-Production
Production
Discontinued
Definition
Information in this datasheet is based on product ideas in the planning phase of development. All specifications are design goals without any warranty and are subject to change without notice
Information in this datasheet is based on products in the design, validation or qualification phase of development.
The performance and parameters shown in this document are preliminary without any warranty and are subject to change without notice
Information in this datasheet is based on products in ramp-up to full production or full production which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of
Trade
Information in this datasheet is based on products which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of
Trade, but these products have been superseded and should not be used for new designs
Page 16
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
AS3728 −
Revision Information
Revision Information
Changes from 1-02 (2014-Dec-16) to current revision 1-03 (2015-Aug-31)
Updated Package Drawings & Markings section
Updated Figure 17
Note(s) and/or Footnote(s):
1. Page and figure numbers for the previous version may differ from page and figure numbers in the current revision.
2. Correction of typographical errors is not explicitly mentioned.
Page
11
13
ams Datasheet
[v1-03] 2015-Aug-31
Page 17
Document Feedback
Content Guide
AS3728 −
Content Guide
Page 18
Document Feedback
ams Datasheet
[v1-03] 2015-Aug-31
