sx1511iultrt Semtech Corporation, sx1511iultrt Datasheet - Page 22

• Manufacturer Part Number: sx1511iultrt
• Description: World
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
4.9.6
When several GPIO expanders are used in the same application it may be useful that their LEDs drivers are
synchronous for coherent global operation.
In this case all ICs should share their fOSC through their OSCIO pins and have their NRESET pins connected
together.
When RegMisc of each IC is set accordingly, NRESET signal can then be used to reset all devices’ internal
counters (but not the register settings) and allow synchronous LED operation (blinking, fading) across multiple
devices.
4.9.7
Below are the steps required to use the LED driver with the typical LED connection described §6.2:
Rev 1 – 24
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
-
-
300
250
200
150
100
50
0
1
Synchronization of LED Drivers across several ICs
Tutorial
Disable input buffer (RegInputDisable)
Disable pull-up (RegPullUp)
1
1
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
10
th
Feb. 2010
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61
62
63
28
37 46
10
10
10
10
11
11
12
12
7
7
8
8
8
8
9
9
9
9
55
64
Figure 18 – LED Driver Linear vs Logarithmic Function (II)
Table 7 – LED Driver Linear vs Logarithmic Function (I)
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
73
82 91 100 109 118 127 136 145 154 163 172 181 190 199 208 217 226 235 244 253
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
RegIOn (4xRegOff[2:0])
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
38
38
39
39
41
41
42
42
44
44
46
46
46
46
49
49
49
49
22
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
World’s Lowest Voltage Level Shifting GPIO
65
65
69
69
69
69
73
73
73
73
78
78
78
78
83
83
83
83
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
with LED Driver and Keypad Engine
SX1510/SX1511/SX1512
104
104
110
110
110
110
116
116
116
116
122
122
122
122
129
129
129
129
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
www.semtech.com
157
157
165
165
165
165
172
172
172
172
181
181
181
181
189
189
189
189
Linear mode
Log mode
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
225
225
235
235
235
235
245
245
245
245
255
255
255
255
255
255
255
255