AK2557

[AK2557]
= Preliminary =
AK2557
4ch Cathode Common LDD with Digital APC
1. General Description
The AK2557 is a 4-channel cathode common LDD (Laser Diode Driver) suitable for MFPs (Multi Function
Printer) and LBPs (Laser Beam Printer). The AK2557 equips a 200MHz [Max.] LDD that switches the LD
current, current-DACs that set the operation current of LD and a feed-back digital APC (Auto Power
Control) circuit that maintains the optical LD power constant. The AK2557 can improve the printing quality
and reduces external parts and the cost with useful functions such as the internal APC adjustment,
BIAS_APC (Auto “Ibias” Setting), LD Power Attenuation and Shading Correction with digital interface
achieving with the internal arithmetic circuits. Multiple AK2557s can be connected to the multi-beams LD
(≥ 8 beams).
2. Features
□ 4ch Cathode Common LDD Switching LD Current at 200MHz [Max]
□ 9-bit Current-DAC for “Ibias”: Maximum Output Current = 45mA [Typ.]
□ 9-bit Current-DAC for “Isw” with AGC (Auto Gain Control): Maximum Output Current = 90mA [Typ.]
□ Feed-Back Digital APC (APC_FB) and Internal APC Adjustment Circuit with Digital Interface
□ Monitor PD Current Input for 4 Beams LD and Multi-Beams LD (by Cascade Connection)
□ “BIAS_APC” (Auto “Ibias” Setting)
□ LD Power Attenuation and Shading Correction
□ Excessive Over-Current Alarm
□ Start-Up Operation (Loading External EEPROM Data and Executing Initial APC)
□ Power Supply: 5V±5% Single Power
□ Package: 48-pin QFN with Exposed Pad
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[AK2557]
3. Block Diagram
R_SW1_I
AK2557
DATAP1
Isw1
IDAC
_SW1
DATA
DATAN1
(LVDS)
R_BIAS1_I
ILD1
IDAC
_BIAS1
CH1
Iop1
Ibias1
LD1
P_ENB*
Common
Digital Circuit
SDCLK
P_SEL*
Parallel I/F
PDMON
PD
Ipd
Mode
Control
vpd
PD
Detector
Comp.
PD
R_APC1_DAC
R_APCx_DAC
Rref
APC
I_APCH1_I
I_APCHx_I
BIAS_APC
DAC_APC
P_SH*
P_CH1*
P_CH0*
P_HL*
Attenuation
Shading
CSI*
vapcref
EEPROM
(MicroWire)
CSO
VREF
Over Current
Alarm
VREFBIAS
Serial I/F
Set-Up
Oscillator
SK
DOI
Power On
Reset
DI
DIO
CHx (x=2, 3, 4)
DATAPx
DATANx
CS
SKOI
R_SWx_I
IDAC
_SWx
Iswx
DATA
(LVDS)
ILDx
IDAC
_BIASx
R_BIASx_I
DO
Ildx
Ibiasx
LDx
With Power Down Protection
BG_FIX*
CUALM
SET* STRT A2 A1 A0
INT_ST
* : With Pulled-Down Resistor
Figure 3.1. AK2557 Block Diagram
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[AK2557]
4. Package
4.1. Outline Dimensions
7.00±0.10
0.40±0.10
B
0.23
+0.07
-0.05
0.10
C0
.60
M
AX
5.1
6.75±0.10
7.00±0.10
6.75±0.10
A
0.50
M
AB
5.1
4.2.
C
0.85+0.15
-0.05
+0.03
0.08
0.02 -0.02
0.20
C
Marking
AK2557
YYWWXXX
a. Pin #1 Index:
Circle
b. Marking: AK2557
c. Date Code: YYWWXXX (7 Digits)
YY: Year
WW: Week (1 ~ 52)
XXX: Manufacturing Identification
AK2557-E-Preliminay0.90 (Brief)
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[AK2557]
IMPORTANT NOTICE
0. Asahi Kasei Microdevices Corporation (“AKM”) reserves the right to make changes to the
information contained in this document without notice. When you consider any use or application
of AKM product stipulated in this document (“Product”), please make inquiries the sales office of
AKM or authorized distributors as to current status of the Products.
1. All information included in this document are provided only to illustrate the operation and
application examples of AKM Products. AKM neither makes warranties or representations with
respect to the accuracy or completeness of the information contained in this document nor grants
any license to any intellectual property rights or any other rights of AKM or any third party with
respect to the information in this document. You are fully responsible for use of such information
contained in this document in your product design or applications. AKM ASSUMES NO LIABILITY
FOR ANY LOSSES INCURRED BY YOU OR THIRD PARTIES ARISING FROM THE USE OF
SUCH INFORMATION IN YOUR PRODUCT DESIGN OR APPLICATIONS.
2. The Product is neither intended nor warranted for use in equipment or systems that require
extraordinarily high levels of quality and/or reliability and/or a malfunction or failure of which may
cause loss of human life, bodily injury, serious property damage or serious public impact, including
but not limited to, equipment used in nuclear facilities, equipment used in the aerospace industry,
medical equipment, equipment used for automobiles, trains, ships and other transportation, traffic
signaling equipment, equipment used to control combustions or explosions, safety devices,
elevators and escalators, devices related to electric power, and equipment used in finance-related
fields. Do not use Product for the above use unless specifically agreed by AKM in writing.
3. Though AKM works continually to improve the Product’s quality and reliability, you are responsible
for complying with safety standards and for providing adequate designs and safeguards for your
hardware, software and systems which minimize risk and avoid situations in which a malfunction
or failure of the Product could cause loss of human life, bodily injury or damage to property,
including data loss or corruption.
4. Do not use or otherwise make available the Product or related technology or any information
contained in this document for any military purposes, including without limitation, for the design,
development, use, stockpiling or manufacturing of nuclear, chemical, or biological weapons or
missile technology products (mass destruction weapons). When exporting the Products or related
technology or any information contained in this document, you should comply with the applicable
export control laws and regulations and follow the procedures required by such laws and
regulations. The Products and related technology may not be used for or incorporated into any
products or systems whose manufacture, use, or sale is prohibited under any applicable domestic
or foreign laws or regulations.
5. Please contact AKM sales representative for details as to environmental matters such as the
RoHS compatibility of the Product. Please use the Product in compliance with all applicable laws
and regulations that regulate the inclusion or use of controlled substances, including without
limitation, the EU RoHS Directive. AKM assumes no liability for damages or losses occurring as a
result of noncompliance with applicable laws and regulations.
6. Resale of the Product with provisions different from the statement and/or technical features set
forth in this document shall immediately void any warranty granted by AKM for the Product and
shall not create or extend in any manner whatsoever, any liability of AKM.
7. This document may not be reproduced or duplicated, in any form, in whole or in part, without prior
written consent of AKM.
AK2557-E-Preliminay0.90 (Brief)
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2015/7