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Based on kernel version 3.16. Page generated on 2014-08-06 21:39 EST.

1	Kernel driver ntc_thermistor
2	=================
3	
4	Supported thermistors from Murata:
5	* Murata NTC Thermistors NCP15WB473, NCP18WB473, NCP21WB473, NCP03WB473, NCP15WL333
6	  Prefixes: 'ncp15wb473', 'ncp18wb473', 'ncp21wb473', 'ncp03wb473', 'ncp15wl333'
7	  Datasheet: Publicly available at Murata
8	
9	Other NTC thermistors can be supported simply by adding compensation
10	tables; e.g., NCP15WL333 support is added by the table ncpXXwl333.
11	
12	Authors:
13		MyungJoo Ham <myungjoo.ham@samsung.com>
14	
15	Description
16	-----------
17	
18	The NTC (Negative Temperature Coefficient) thermistor is a simple thermistor
19	that requires users to provide the resistance and lookup the corresponding
20	compensation table to get the temperature input.
21	
22	The NTC driver provides lookup tables with a linear approximation function
23	and four circuit models with an option not to use any of the four models.
24	
25	The four circuit models provided are:
26	
27		$: resister, [TH]: the thermistor
28	
29	 1. connect = NTC_CONNECTED_POSITIVE, pullup_ohm > 0
30	
31	   [pullup_uV]
32	       |    |
33	      [TH]  $ (pullup_ohm)
34	       |    |
35	       +----+-----------------------[read_uV]
36	       |
37	       $ (pulldown_ohm)
38	       |
39	      --- (ground)
40	
41	 2. connect = NTC_CONNECTED_POSITIVE, pullup_ohm = 0 (not-connected)
42	
43	   [pullup_uV]
44	       |
45	      [TH]
46	       |
47	       +----------------------------[read_uV]
48	       |
49	       $ (pulldown_ohm)
50	       |
51	      --- (ground)
52	
53	 3. connect = NTC_CONNECTED_GROUND, pulldown_ohm > 0
54	
55	   [pullup_uV]
56	       |
57	       $ (pullup_ohm)
58	       |
59	       +----+-----------------------[read_uV]
60	       |    |
61	      [TH]  $ (pulldown_ohm)
62	       |    |
63	      -------- (ground)
64	
65	 4. connect = NTC_CONNECTED_GROUND, pulldown_ohm = 0 (not-connected)
66	
67	   [pullup_uV]
68	       |
69	       $ (pullup_ohm)
70	       |
71	       +----------------------------[read_uV]
72	       |
73	      [TH]
74	       |
75	      --- (ground)
76	
77	When one of the four circuit models is used, read_uV, pullup_uV, pullup_ohm,
78	pulldown_ohm, and connect should be provided. When none of the four models
79	are suitable or the user can get the resistance directly, the user should
80	provide read_ohm and _not_ provide the others.
81	
82	Sysfs Interface
83	---------------
84	name		the mandatory global attribute, the thermistor name.
85	
86	temp1_type	always 4 (thermistor)
87			RO
88	
89	temp1_input	measure the temperature and provide the measured value.
90			(reading this file initiates the reading procedure.)
91			RO
92	
93	Note that each NTC thermistor has only _one_ thermistor; thus, only temp1 exists.
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