LM93 datasheet(40/95 Pages) TI1

40 / 95 page

LM93

SNAS210E – DECEMBER 2003 – REVISED MARCH 2013

www.ti.com

This ramp function operates independently for VRD1_HOT and VRD2_HOT. In addition, the ramp function

only applies to the PWM(s) that are bound to one or two VRDx_HOT inputs. Depending on the bindings, it

is possible that up to four independent ramp functions are active at any given moment:

PWM1/VRD1

PWM1/VRD2

PWM2/VRD1

PWM2/VRD2

If a PWM is bound to both VRD1_HOT and VRD2_HOT, then two ramp functions are active for that PWM

output. In this case the duty cycle that is used is the maximum of the two ramp functions.

3.16.10.9 PROCHOT Ramp-Up/Ramp-Down

This function is very similar to the VRDx_HOT ramp-up/ramp-down function. The PWM duty cycle ramps

up in the same fashion whenever the PROCHOT measurement exceeds the user programmed threshold.

Once a new PROCHOT measurement is made that no longer exceeds the user limit, the PWM will begin

to ramp down.

Just as with the VRDx_HOT ramp function, the PROCHOT ramp function uses independent bindings to

determine which PWM outputs should be effected by each PROCHOT input (P1_PROCHOT or

P2_PROCHOT).

If a PWM is bound to both P1_PROCHOT and P2_PROCHOT, two PROCHOT ramp functions could be

active at the same time. In this case the duty cycle that is used is the maximum of the two ramp functions.

3.16.10.10 Manual PWM Override

When a PWM channel is configured for manual PWM override, software can manually control the PWM

duty cycle. There are some PWM control functions that could still cause the duty cycle to be higher than

the manual setting. See the Fan Control Priorities for details.

3.16.10.11 Fan Spin-Up Control

All of the other PWM control functions are combined to produce a final duty cycle that is actually used for

the PWM output. If this final value changes from zero to a non-zero value, the Fan Spin-Up Control

function is triggered. Once triggered, the Fan Spin-Up Control requests the programmed duty cycle for a

programmed period of time.

3.16.11 XOR TREE TEST

An XOR tree is provided in the LM93 for Automated Test Equipment (ATE) board level connectivity

testing. This allows the functionality of all digital inputs to be tested in a simple manner and any pins that

are non-functional or shorted together to be identified. When the test mode is enabled by setting the ‘XEN’

bit in the XOR Test register, the part enters XOR test mode.

The following signals are included in the XOR test tree:

SPACER

Px_VIDy

GPIO_x

PWMx

Px_PROCHOT

VRDx_HOT

SCSI_TERMx

RESET

Functional Description

Submit Documentation Feedback

Product Folder Links: LM93

LM93 Datasheet(PDF) 40 Page - Texas Instruments

LM93 Datasheet(HTML) 40 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

Datasheet Download

Link URL