Datasheet
LM75B All information provided in this document is subject to legal disclaimers. © NXP B.V. 2015. All rights reserved.
Product data sheet Rev. 6.1 — 6 February 2015 16 of 37
NXP Semiconductors
LM75B
Digital temperature sensor and thermal watchdog
8. Application design-in information
8.1 Typical application
8.2 LM75A and LM75B comparison
[1] This option is updated to be compatible with the competitive parts. When the OS output has been activated in the interrupt mode due to
a temp limit violation, if the Configuration Shutdown bit B0 is set (to the LM75A), then the OS output activated status remains
unchanged, while (to the LM75B) the OS will be reset. The latter is compatible with the operation condition of the competitive parts.
[2] The LM75 series is intentionally designed to provide two successive temperature data bytes (MSByte and LSByte) for the 11-bit data
resolution and both bytes should be read in a typical application. In some specific applications, when only the MSByte is read using a
single-byte read command, it often happens that if bit D7 of the LSByte is zero, then the device will hold the SDA bus in a LOW state
forever, resulting in a bus hang-up problem, and the bus cannot be released until the device power is reset. This condition exists for the
LM75A but not for the LM75B. For the LM75B the temperature can be read either one byte or two bytes without a hang-up problem.
[3] The bus time-out is included for releasing the LM75B device operation whenever the SDA input is kept at a LOW state for too long
(longer than the LM75B time-out duration) due to a fault from the host. The trade-off for this option is the limitation of the I
2
C-bus low
frequency operation to be limited to 20 Hz. This option is compatible with some of the latest versions of the competitive parts.
[4] The data hold time is improved to increase the timing margin in I
2
C-bus operation.
Fig 13. Typical application
002aad457
0.1 μF
10 kΩ
DIGITAL LOGIC
LM75B
DETECTOR OR
INTERRUPT LINE
BUS
PULL-UP
RESISTORS
I
2
C-BUS
8
2
SCL
SDA
A2
A1
A0
5
6
1
7
4
3
OS
V
CC
power supply
GND
10 kΩ10 kΩ
Table 15. LM75A and LM75B comparison
Description LM75A LM75B
availability of the XSON8U (3 mm 2 mm) package type no yes
OS output auto-reset when SHUTDOWN bit is set in interrupt mode
[1]
no yes
support single-byte reading of the Temp registers without bus lockup
[2]
no yes
bus fault time-out (75 ms, 200 ms)
[3]
no yes
minimum data hold time (t
HD;DAT
)
[4]
10 ns 0 ns
ratio of conversion time / conversion period (typical)
[5]
100 ms / 100 ms 10 ms / 100 ms
supply current in shutdown mode (typical value) 3.5 A0.2A
HBM ESD protection level (minimum) >2000 V >4500 V
MM ESD protection level (minimum) >200 V >450 V
CDM ESD protection level (minimum) >1000 V >2000 V