S3F84B8 All-in-One IH Cooker Revision 0.00 May 2010 Application Note 2010 Samsung Electronics Co., Ltd. All rights reserved.
Important Notice The information in this publication has been carefully checked and is believed to be entirely accurate at the time of publication. Samsung assumes no responsibility, however, for possible errors or omissions, or for any consequences resulting from the use of the information contained herein.
Revision History Revision No. Effective Date 0.
Table of Contents 1 OVERVIEW OF IH COOKER (IHC) .............................................................1-1 1.1 Induction Cooking Principle ..................................................................................................................... 1-1 1.1.1 How Induction Cooking Works ......................................................................................................... 1-1 1.2 Key Features of S3F84B8.........................................................................
List of Figures Figure Number Title Page Number Figure 1-1 Figure 1-2 How IH Cooker Works ...................................................................................................................... 1-1 Pin Assignment in S3F84B8 ............................................................................................................. 1-2 Figure 2-1 Figure 2-2 Figure 2-3 Figure 2-4 Figure 2-5 Figure 2-6 Figure 2-7 Figure 2-8 Figure 2-9 Block Diagram of IH Cooker System ....................
List of Tables Table Number Title Page Number Table 2-1 S3F84B8 pin assignment in IH cooker system .................................................................................. 2-5 Table 3-1 Internal Resource Arrangement and Configuration ........................................................................... 3-4 Table 4-1 Error Information ................................................................................................................................
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 1 1 OVERVIEW OF IH COOKER (IHC) OVERVIEW OF IH COOKER (IHC) In traditional ranges or ovens, cookware is used to transfer heat from the stove elements. However, in the IH cooker (IHC), the cookware participates in the heat generation. This form of heat generation is known as Induction Heating, and it improves the overall thermal efficiency of heating.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 1 OVERVIEW OF IH COOKER (IHC) 1.2 KEY FEATURES OF S3F84B8 With no more discrete ICs like LM339 (comparator IC) in previous IHC solutions, S3F84B8 successfully integrates four comparators, one OPA, and one IH-PWM to control power directly. After configuration, all the four comparators can cooperate with the IH-PWM automatically, which makes the time-sensitive control possible. Figure2 shows the pin assignment in S3F84B8. VSS 1 20 VDD INT0/XIN/P0.0 2 19 P2.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 1 OVERVIEW OF IH COOKER (IHC) Comparator1/2/3 has only one input with an internal programmable reference level. It can lock the output of PWM to a safe level. Besides the delay trigger function, PWM can realize anti-mis-trigger function as well. It prevents the PWM from being triggered by unexpected noise. For more information about the cooperating mechanism of the IH-PWM and four comparators, refer to the user’s manual. 1.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 2 HARDWARE IMPLEMENTATION HARDWARE IMPLEMENTATION 2.1 SYSTEM DIAGRAM AND PIN ASSIGNMENT Figure 2-1 shows the block diagram of IH cooker system.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION In Figure 2-1, SMPS stands for Switch Mode Power Supply. It provides +18V DC and +5V DC to the system. Three out of four comparators are used in this solution: one for synchronization circuit and other two for surge protection and IGBT over-voltage protection. Table 2-1 shows the pin assignment while using S3F84B8 in IH cooker system. Table 2-1 S3F84B8 pin assignment in IH cooker system Pin No.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.2 POWER SUPPLY Figure 2-2 shows the circuit diagram for power supply. D6 AC_L 220 VAC D7 1N4007 D1 L1 T1 D4 UF4007 1 AC_N 1N4007 +18V 5 D7 UF4007 330uH R1 100K/0.5W 1N4007 + C2 4.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.3 SYNCHRONIZATION CIRCUIT +18V R28 51R R22 2K D8 4148 COOKER R21 2K C28 + 25V/100uF Q4 8050 L2 FUSE1 1 AC_L L3 - + C23 102 10R IGBT IGBT_CTRL FGA15N120 4 4uF/400V PWM Q2 8050 Q5 C17 R37 10K BRIDGE D15XB80H18 101 R24 1K R50 CONSTANTAN 3 AC_N R23 2K 8550 C20 0.24uF/1200V C19 C22 2 0.1uF/275V Q1 8050 R36 CHOKE 10A/250V IGBT Driver SYS_I R2 220K/0.5W R6 220K/0.5W R3 470K/0.5W R10 470K/0.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION IH heating is the result of Eddy current caused by LC resonance. For a general cookware, the oscillation frequency may vary from 20KHz to 30KHz. Since heating consumes energy, the IGBT should be periodically turned on to allow the 220V power to compensate for the energy loss. Obviously, the longer it is turned on, the more energy can be accumulated.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.4 POWER CONTROL Power is the product of voltage and current (P = V x I). Figure 2-5 and Figure 2-6 show the measurement circuit of system voltage and current, separately. 2.4.1 VOLTAGE MEASUREMENT Figure 2-5 shows the circuit diagram for voltage measurement and surge protection. 1N4007 D9 AC_L 220 VAC D10 AC_N 1N4007 surge protection Surge_P R17 470K/0.5W R18 R19 820K/0.5W 820K/0.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.4.2 CURRENT MEASUREMENT SYS_I OPA_N R4 1K RW1 R13 36K C10 104J Rf OPA_O R14 100K R15 22K 10K CURRENT R1 OPA _ N OPA _O + C12 1uF/16V OPA _P 3F84B8 S Gain = -Rf/R1 Figure 2-6 Current Measurement Circuit In the IH cooker system, the current can go as high as 10A. To avoid excessive energy loss, a constantan is used to change the current signal to voltage signal, which is then amplified by the integrated OPA.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.5 SYSTEM PROTECTION 2.5.1 SURGE PROTECTION Figure 2-5 shows the circuit diagram for surge protection. In this figure, Surge_P specifies the negative input of Comparator 1. Also, reference voltage is internally set as 0.55VDD. When surge takes place, that is, V Surge_P > 0.55VDD, the falling edge of comparator 1 can hard-lock the PWM output immediately to prevent the IGBT from being burnt out by over current.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.5.4 TEMPERATURE PROTECTION Figure 2-7 shows the circuit diagram for temperature protection. +5V CN5 RT1 100K3950 2 1 PAN_T +5V IGBT_T C25 R29 104 3K T_PAN C4 104 R5 10K b) IGBT temperature protection Figure 2-7 a) Pan temperature protection Over-Temperature Protection RT1 is a thermistor located just beneath the IGBT. CN5 is the connector for the thermistor near the pan.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.6 OTHER FUNCTIONS 2.6.1 PAN DETECTION Pan-on detection is executed every 2sec when the system is idle. It is useful when you press the Start key first and then put the pan on. In principle, even though the IGBT is turned on, there will not be any oscillation before the pan is put on the panel. In S3F84B8, comparator 0’s output can be set as the clock source of Timer C.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION 2.6.3 KEY AND DISPLAY CIRCUIT Figure 2-9 shows the circuit diagram for key and display.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 3 3 SOFTWARE IMPLEMENTATION SOFTWARE IMPLEMENTATION 3.1 STATE TRANSITION DIAGRAM Figure 3-1 shows the state transition diagram. This diagram illustrates the operation of IH cooker system. Figure 3-1 State Transition Diagram After power is turned on manually, the system periodically checks for pan status and current work condition. This ensures the power is activated only when the pan is on panel, and all temperatures and voltage are in good condition.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 3 SOFTWARE IMPLEMENTATION 3.2 SOFTWARE DIAGRAM Figure 3-2 shows the software diagram. Figure 3-2 Software Diagram NOTE: 1. 2. [1] Pan remove detection [1] is done by current sensing. The pan is judged to be removed when the current is lower than a preset threshold. [2] Pan on detection [2] is done by pulse counting. The pan is judged to be put on when the counted pulse number is between 1 and 3 during 3 oscillation period.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 3 SOFTWARE IMPLEMENTATION Figure 3-3 shows the flow chart of CMP1/2 interrupt service routine. Due to the cooperation of IH-PWM and comparators integrated in S3F84B8, only a few jobs need to be done in the ISR. CMP1INT ISR (hard lock) For surge protection CMP2INT ISR (soft lock) For IGBT over voltage protection Start Start Clr pending bit Clr pending bit Set P0.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 3 SOFTWARE IMPLEMENTATION 3.3 INTERNAL RESOURCE ARRANGEMENT AND CONFIGURATION Table 3-1 shows the internal resource arrangement and configuration. Table 3-1 Module CMP0 Internal Resource Arrangement and Configuration Purpose Configuration Synchronization Non-inverting output Disable INT Registers CMP0CON CMPINT P1CON CMP2 CMP1 OPA Surge protection IGBT over-V protection Current amplification 0.
S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 4 4 APPENDIX APPENDIX 4.1 ERROR CODE Table 4-1 shows the error information along with the error type and its code on 7seg-LED. Table 4-1 Error Information Error Type Error code on 7seg-LED IGBT temperature sensor error E1 Pan temperature sensor error E2 Over voltage error E3 Under voltage error E4 IGBT over temperature error E5 Pan over temperature error E6 4.2 SCHMATIC S3F84B8_DEMO_V0.0 _0401.pdf 4.
